Glad to see that I am not the only one that views the majority of Vainilla V civs as vastly inferior as the new ones. I would really like to make a mod in order to solve this issue, but I would like to wait and see what the original game designers come up with, since the other previous redesigns (France and Arabia) were truthly genious.
As for which civs I would like to see remade:
Germany: Change its UA, buff the Panzer, replace the Landsketch
Horribly represented civ, both in terms of balance and flavour. Where's industrial Germany, the XVIIIth century nation of poets and philosophers and the current economic powerhouse of Europe? It also doesn't help that its UA is a mish mash of other UA's for maximum boredom. Change it Firaxis, please.
Japan: Change its UA, remake the Samurai, Replace the Zero
Another of the worst designed vainilla Civs, also suffering from balance and flavor issues or "warmonger-itis". I think that both a war - like and cultured type of civ would suit Japan, or they could make it a scientific civ if they want, seeing how there are so little of these in the game. Either way, playing with Japan is just... boring.
America: Change its UA into something that it is actually worthwhile and / or interesting. Perhaps even replace one of its UU
America, obsolete at the discovery of the Soshone. Nuff said. Not to mention that passive type of bonuses like the ones of its UA, doesn't lead to any kind of change into playstyle or strategy. That's bland as hell. Also, albeit both its UU are decent, the bomber comes too late to make any kind of meaningful difference.
India: Change everything. Tear it down, rebuild it again.
Ill designed from day one, it is also quite dissapointing to see that from all the angles that such a rich culture such as India offers, they just opted for popullation and... elephants. Gotta design an American Civ with a cowboy based UU, I guess.
Ottomans: Change its UA
Its UU are cleverly designed, but they really ougth to change their UA, which has a severe overlap with Germany's and the "Convert the heathen" reformation belief, not to mention that they are yet again another "warmongered" civilization.
The Celts: Change its UA and UB
Whichever differential advantage they might have, it dissappears by the time the race for the pantheon is over, that is, extremely early. Its UU is well designed and it has been buffed by the latests BNW changes, but its UB is as generic as it goes.
Egypt: Change its UB
I cannot believe that archeology is introduced yet it hasn't affected Egypt. Some kind of bonus towards artifact generation in their lands, would be in order, me thinks.
The Dutch: Change its UA, tweak its UI
Their UA is completely meaningless with the new mechanics (no more early lump sum gifts), and the introduction of the trade routes just scream for some kind trade route related UA. Also, the Polder, even if it is an awesome improvement, it is quite ill -represented in game, me thinks (shouldn't it be built on coasts instead?).