I personally like to play as either the Koreans, Huns or the mongols and get to the castle age as quickly as possible like Fifty said, then max out on the castle unit, cavaliers or paladins, and champions once all are attainable. You need champions (mixed with some halberdiers/pikemen) to crush the enemy's pikemen and protect your cavalry-heavy army.
If you like fast castle you'd be much better served by different civs. Specifically, trying to fast castle vs. a meso fast castle (aztecs mainly) will end very very very badly for the hun/mongol/korea player. aztecs are
the fast castle/fast imp civ. In fact, on open land maps aztecs are the best in the game.
If you are playing conquest/deathmatch mode and start in the Imperial Age, then build about 6-7 stables and 4 castles. Build another 2 stables and 1 castle away from your base, plus about 3 town centers near your base.
This isn't very good advice for deathmatch. You're going to want to build many more stables and focus less on early castles (unless you are doing an advanced strat like a korea or saracen castle clump). Barracks should also be built for halberdiers.
Get about 30 paladins/cavaliers plus 30 castle units of which ever civ you are. Rush the enemy base as quickly as possible. Back it up with Champions and onagers if you can.
You're going to want WAY more units than that, and focus less on unique units. The only civ that ought to make especially heavy use of unique units in deathmatch are koreans, spanish, and goths, and the goths build their unique unit from barracks. Huns' unique unit is pretty crappy. The mongol unique unit is good only in certain esoteric settings (like fortress regicide).
This can easily take out AT LEAST one unsuspecting opponent, two if you are very efficient and timely. Very quick scouting before attack would do a lot of good so you attack the right opponent. What I mean is if you are rushing with a War Elephant + Onager army, do not attack an infantry-heavy opponent.
an army of siege onagers in DM is a very bad idea with any civ except Korea.
The most common rush tactic for DM is to play huns, make 15 or so stables right away (and either defned your vils or raid your opponents' with your hussar) and just go nuts with halberdiers, paladins, and hussars, all while building up an economy and establishing a line with your allies to create a trade route.
I personally have been demolished by the Persians and Koreans before in Multi-player, literally demolished, so those would be good choices for people familiar with them (The Koreans have much better all-round units and tower power in my opinion though).
The koreans are overpowered and banned from competitive DM play. As for regular non-DM, koreans are one of the worst civs in open land maps, which is definitely the most common setting. They are pretty good on land nomad, black forest, and michi though, which are common game-types played by rookies.
The Huns are excellent for rushing since you don't need to build houses. Just build 4-5 castles right off the bat, plus 6 stables, and keep pumping out the cavalry. Don't rush/attack until you have about 30 of each, then use them all on one opponent to get full use of power. Keep them coming though, since you will surely be attacked by someone else while you're attacking.
That's decent advice except you are overephasizing early castles. Huns especially, with their rather lackluster unique unit, do not need to be building early castles on deathmatch.
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