Persia. The Immortals were nearly unstoppable early in the game.

Taking OP's point seriously, it would have to be the Hellenic Empire/Greek Civilization. So much the followed in world history was influenced by them, and I always love playing the what if game on what would've happened had Alexander not died when he was 26 (?)

32, my bad

@2nd - I always played as the Teutons. Teutonic Knights were just so strong.

@gold - I would have to say that right about now Greek Civilization is probably my fave, but honestly, Greek civ is probably the most obvious choice, and I think by the end of the semester it will probably change to a less obvious civ.

Rome, without question.

I have to admit I'm something of a fan of the modern civilization. Rome is good and all, but I couldn't be dealing with communal toilets.

I always had an abiding love of the Norse and other Northern mythologies. Icelandic sagas are great reading and every bit as interesting as the Iliad/Odyssey/Aeneid.

Assyrians. Way ahead of their time in terms of political organization and military organization. Badasses.

+1 for Assyria. They were pretty fucking cool.

Octo,

You're a bit more squeamish than I expected.

It is something I could endure, but you wouldn't want to live with it. France is similar in many ways

Vive la France!

Byzantine.
http://12byzantinerulers.com

Ottoman Empire.

Byzantine. The weirded-out continuity with the Roman Empire, the ferocious ambivalence between iconoclasts and the magnificent icons, and the fact that there were two opposing factions represented by colors that could not be more alike, the "Blues" and the "Greens", fighting over hairsplitting differences about anything.

The Roman Empire. Obvious choice I know, but their towering greatness is undeniable, and their legacy unsurpassed.

While I do love Greece and Egypt, they're both rather obvious. I have some soft spots for the Habsburg Empire and the Republics of Venice and Tuscany.

The mongols were definitely my favorite empire...

The Mongols because they were the exception to every rule of great civilizations that ever existed, particularly in that they didn't exactly last very long.

Oh I got sniped.

Meh.

I think we have to distinguish here between empires and civilizations. For example, the Portuguese empire was very large and rich, but I honestly can point to nothing that would lead me to call them a separate civilization.

My favorite civilization is tough to define. For one, does medieval europe count as a civilization, or can it be separated?

For antiquity, gotta be the Chinese in some periods, with Greeks Egyptians not too far behind.
Medieval times is tough. I like the arab civilization, what with Cordoba and all. Great cultural and scientific advancement. The Chinese get another mention. I also like the Italian merchant republics for a lot of reasons, though I wouldn't choose to be there.
1492 to end of Napoleonic wars, France is pretty tempting because of sheer power, and the Ottoman Empire is too. Neither are civilizations I really like though.
End of Napoleonic wars to 1919, France again, at least for the third republic and the Belle epoque. Otherwise, it's really difficult, honestly. Before the third republic, I can't really think of a civilization that I like.
1919-1945, probably France. They tried to fight the Germans and got their asses kicked for it. Then they had an extensive resistance network.
1945-now, much harder to like France, considering how they "handled" decolonization. Culturally, I still like France, and they are at least trying to help out in a good number of places, but I can't call them my favorite civ. Don't really have a favorite civ right now.

The Mayans at least deserve a mention. Especially in that they were making a lot of the same advances that Old World civilizations were, but doing so in relative isolation. In some cases (especially in mathematics & astronomy) they were more accurate.

Yeah, those guys definitely count too.

The Incas were pretty cool, too.

I'd go for Britain 1640-60 when there was free press and free religion. Not a ciivilisation but an unprecedented amount of free thinking going on - a philosophers wet dream.
Chaps, sorry to jump in mid discussion, but I desperately need a player:
1 more player needed. Anonymous, public press. http://www.webdiplomacy.net/board.php?gameID=146904
pssword id either spinitback or slamitdown (sorry, I can't remember)
Please join so we can kick this mother off