Just a warning: This is going to be a looooong post, but an awesome one. Makes me really sad my old computer died, because this was on there.
My greatest war, with some awesome battles involved, was a Emperor level game when I was playing as Bismark, on a world map (I think it was Marla Singer's, but I'm not certain), against Mao. Probably the coolest game I ever played, period. First, a lot of background, to explain how awesome a game this was:
The 24 Civs that started this game were Germany (me), England, France, Russia, Rome, Ottomans, Egypt, Zululand, America, Mayas, Incas, China, India, Japan, Persia, Arabia, Carthage, Iriquois, Aztecs, Babylon, Carthage, Greece, Spain, and Scandinavia, all in the real-life starting positions (well, the positions of their capitals). I very quickly isolated Rome by building a city in Northern Italy, and making it into a fortress. I worried about consolidating Central Europe, keeping the French from expanding east, and the Russians from expanding west. I also exanded into the Balkans, competing with Greece and Turkey for land and resources there. To this point, there had been no war on my side of the world, as everyone had ample room to expand, excepting the Romans. That soon changed.
I eliminated France and Spain, gobbling up their territory, before taking to fight to the Greeks and Ottomans, pushing them out of Europe, eliminating the Greeks in the process. Followed this up by doing the same to Rome, then began siezing the islands of the Mediterranean. Conquered Cathaginian North Africa, then Egypt, then took the Babylonian and Ottoman cities along the Mediterranean coast. England developed Map Making, so I destroyed them before they could contact the other nations. The Vikings and Russians began fighting one another, as Russia had hemmed Scandinavia in as I had the Romans, and they wanted out. I picked off the Scandinavian navy, but left their cities alone, letting Russia weaken itself. Then I switched sides, pushing the Russians out of Europe, before turning on the Vikings, leaving them only Iceland, as I figured they could build me a suitable industrial base there which I could take later.
With Europe mine, and the tech advantage, I then proceeded to turn my knights loose on the Middle East, pushing the Babylonians, Persians and Ottomans into Central Asia and Siberia, and the Arabs into the sea and Africa. This gave me a border with powerful India, which I left alone for now, letting it balance China. I turned my attention to a mass colonisation of Africa, fighting Carthage for the privelege when they got too aggressive. Once West Africa was mine, I put the Carthagians out of their misery, and forced the Egyptians into Central Africa, and Arabia permanently out of the Afro-Asian landmass.
After that, I busied myself establishing an Empire in North America, using the fighting of the native states among themselves to take the entire Eastern North America, then finished off the Egyptians, conquered the Zulus, which included Madagascar, and took bits and pieces of South America that were of strategic value.
Meanwhile, China had become the runaway AI Civ of this game. It had very quickly spread along the coastling in China and Manchuria, controlling Korea in the process. They fought a war with India when both tried to settle Southeast Asia, with china winning. They then expanded into Southeast Asia, before fighting a second, inconclusive war with India, which held them off due to its Ancient Cavalry. They did gain a few cities though, and foorced the Indians to forget land expansion, and concentrate on the sea, competing with the Arabs.
China eliminated Japan when they gained Map Making, in the same manner I'd removed the English, then fought off expansionist Russian and Ottoman regimes in Mongolia. They and the Persians wiped out the Ottomans, before turning their attention to Babylon, removing it too. India had expanded into Tibet, and these three Civs established an equlibrium in the area, with China strong enough to defeat one, but not both, but neither side strong enough to defeat China, and both fearful of me as well. Persia and India signed an MPP as soon as they aquired Nationalism.
Meanwhile, Russia dominated Siberia and much of East Asia, and the Chinese wanted it. They fought a thousand year war against Russia, culminating in the subjugation of Russia. They then settled the few unsettled regions of Northeast Asia, took the eastern half of the Indonesian archipelago and Australia, sharing them with India, which had conquered the Arabs by this point, along with the Phillipines, Taiwan, and every single Pacific Island. They then entered North America, bringing me in direct contact with them for the first time, and destroying both the Americans and the Aztecs in the process.
By this point all four surviving Eurasian nations were in the Modern Age, with the Incas and Mayans a little behind, and the Iriquois pathetically in the Middle Ages, confined to the tundra in Canada. I finished them off, while China fought the Maya. Not wanting China to take the Panama Canal, but fearing a confrontation with them with their superior forces in North America, I entered the war myself, taking the southern half of Central America, the entire Caribbean, and wiping out the Mayas in Eastern South America.
I then built the Manhattan Project, and began stockpiling nukes. The Chinese did the same. We came to an agreement to destroy Persia, which had built a decent sized empire with excellent infrastructure in Central Asia. India was helpless to stop us, but capable of fending off Chinese attempts to invade their territory in Asia. The Chinese did however, take all of Australia, and I liberated India of a few strategic islands myself.
Now China and I bordered each other in Both Eurasia and North America. I strengthened the Incas, not willing to devote my time to conquering them, but also unwilling to see them fall to China. They signed an MPP with India, essentially making them a third Civ, while China and I were the undisputed superpowers. I had a slight lead in tech, and more land, but China had a larger military. We were both democracies, I had a greater number of ICBMs than China, well spread out over a number of cities. I was looking for a Space Race win, as China's culture and mine were too close for a Culture victory, and I didn't see any chance of a domination or Conquest win.
Then China struck, in a war I've never seen a Civ do, before or since. It wasn't merely intelligent, it was frigging brilliant. They must have had a far superior espionage system than I did, because they knew where every single ICBM I had was. They proved this, by sneak attacking me - with nukes. They nuked my capital, which was building my spaceship, throwing nuke after nuke at it until one slipped through the SDI. They then nuked m entire ICBM force, in more than fifty different cities. I repeat: They nuked my entire ICBM force, in more than fifty different cities. They then nuked New Persepolis, on our Eurasian border, and poured Modern Armour and Mech. Inf. in through it, simultaneously bombing the piss out of me, and using more than two dozen marines to take the Panama Canal, after bombing it too.
I couldn't believe it. I had never thought the AI was even capable of such a brilliantly executed strike. I doubt there are many humans capable of doing something that skillful. Nevertheless, I fought back.
I had three Nuclear Subs near Beijing. I used the nukes they carried to take out Beijing, which was building a spaceship. I attempted to get India and/or the Incas on my side, but they refused. Thankfully, they also didn't join the Chinese. I rushed my forces to Central Asia, taking the fight to the Chinese invaders there. I used my navy in the Caribbean to take back the Panama Canal, at a heavy cost, and eliminated all their transports in the area, to keep them from taking it back. They struck back by conquering the entire former Iriquois territory in a single turn, and nuking my fleet in the Caribbean. They also forced me back, using Tactical Nukes, in Central Asia. I hit back with the few tactical nukes in my possession myself, wiping out several armies in Central Asia, and pushing what was left of my Caribbean fleet into the Atlantic, hoping to keep their fleet busy there.
Next, I managed to get few ICBMs, and used them to target their major industrial cities, destroying both the Hoover Dam and the Iron Works in the process, seriously damaging their industry. I followed up by by managing to get Japan to revolt, giving them a problem just off their capital, since they'd destroyed my Subs there, and I couldn't risk moving Carriers into the area yet. They hit back by landing troops in Scandinavia, taking a few cities. This reminded me that the Vikings were still around, and although backward and limited, potentially useful. I gave them every tech I had, allied them against China, and watched them use their backward fleet as a buffer against Europe and the Chinese navy. I took back Scandinavia, retook all my Central Asian cities, and prepared to make China pay.
India, sensing an opening, attacked both me and China, taking several of their former cities in Australia, Southeast Asia and a few islands from me. I responded by strengthening my border with them, destroying their ships off Africa, and otherwise ignoring them. China, dependent upon the rubber in Southeast Asia, had to respond by counterattacking and defending these resources. This gave me an opening.
While China's armies were facing off against India in Southeast Asia, I caught them in their flank, taking Japan in a single turn, who's people welcomed me with open arms. I now had air bases within range of Beijing, and the Chinese knew this, using their few remaining nukes to turn Japan into a bunch of size 1 and 2 cities. Unperturbed, I took Taiwan, Okinawa, and the Phillipines, forcing the Chinese to continue to use every nuke they built just off their own coast. The Incas had entered the war against China, but not against me, and I made peace with India, giving them all the now useless cities off the coast of China. The Incas and I proceeded to deprive China of the Pacific, while the Chinese destroyed the small, backward Scandinavian empire in Iceland, Greenland, and other assorted islands. The Central Asian and Indonesia fronts remained static, while China regained all Southeast Asia and Australia.
I then took the Viking kingdom off China, as I obviously controlled far greater forces in the area. My industrial base was stronger than theirs, so the longer the war went, the more likely a German victory seemed. China, however, had different plans. Mao retook the cities I'd given to India, outflanked them in Indonesia, and took firm control of Tibet, lengthening his front against me. I was forced to thin my troops to defend myself. Meanwhile, his fleet had snuck up on the Incas, and he deprived them of several of their larger cities. Both the Incas and the Indians made peace, and it was one on one again.
Neither one of us could spare the production necessary for a spaceship, so this game came down to Domination or conquest. I nuked Tibet, then flanked Mao in Mongolia, taking true Chinese cities for the first time. Furious, he managed to take both the Cape of Good Hope and Tierra Del Fuego off me, seriously limiting my navies in those areas. I nuked his roads linking Southeast Asia to his industrial heart in China, and blockaded his harbour cities in Indonesia, depriving him of rubber for about three turns. It was enough.
I retook the Iriquois territories in North America, then forced him off the continent with a blitzkrieg, using forces fresh from the invasion of the Viking Kingdom. The Incas, at my prodding, rejoined the war and took back their South American cities. India tried the same, but got nuked mercilessly for their trouble, and I then faced the problem of China taking all of North India, and attacking me in Persia. I responded by taking Delhi with troops from Tibet, and bottling an army between those troops and Persia. Once I destroyed that large army in such a small territory with a few Tactical Nukes, China was done.
Mao was desperately suing for peace over the last ten turns, even after he managed to get both India and the Incas to join the war against me, much to my surprise, although it was too late for them to be anythng but a nuisance. I took Korea, then Japan, then Beijing itelf. The Chinese capital moved to Tsingtao, but that was taken next turn. China was soon forced out of mainland Asia, and the Indians weren't far behind. With the Incas now the main industrialised competitor, I forced them into the Pacific, before wiping out the Indians in the Indian Ocean, then invading what was left of China in Australia and the pacific. The Incas fell, then all chinese territory outside of Australia, then finally New Mecca, the last Chinese City, roughly where Sydney is. And so I won the most awesome game I ever had, b conquering the world in 2018AD.
(I needed the warriors for MPs). But, like I said, Rome was crowding me badly. Besides, they had great land with lots of grass and hills. (On the other side of me was desert . . . ) I knew that they had Iron Working, but I hadn't seen any Legionaries (sp?), so I figured that I'd better strike before they got them.
Their stand was indeed courageous. Ultimately futile, but courageous nonetheless! 
