Greek civilzation influenced the Romans, so Greeks should most of the credit for Western Civilization and Western ideals (democracy, language, monogamy, and so forth).

Other than the obvious Middle Eastern Empires (Egypt, Babylon), we should also consider Chinese and Indian civilizations. They made huge contributions to civilization, from gunpowder to mathematics, but if you live in the West you probably didn't cover that much in school, so you think they weren't as important.

Maybe the Greeks or Romans, but the British shaped so much of the modern world and I love Lucy Pinder's tits, so I'll vote for them and, by extension, the British Empire.

Why not count Byzantine? They lasted a hell of a lot longer than the Western Roman Empire.

This right here.

I'm surprised that no one voted Islamic =/ Remember guys, they were the ones that preserved and will eventually pass on the Renaissance to the Europeans. At one point, the Europeans were the religious extremists, and the Islamic people the tolerant and liberal civilization (until the constant attacks on them made them more conservative and militant).

Really I have to with the Roman Empire/Greek Civilization followed by the Spanish Empire. It's really hard to judge the American superpower right now considering it hasn't fallen yet or ended its reign. Can't judge the scope of its influence until we've seen it lose that influence (and it eventually will but who knows when).

So until we are able to judge that going with the Romans who had Greek influence of course. It's hard to find anything in western civilization that doesn't have some roots back to the Romans. Which is why I can't really give it to the British or Spaniards who have their influence from the Romans/Greeks. Truly the culture the Greeks and Romans crafted was one of the most influential in the world even til this day. And I think a lot of that just has to do with so many people in the west being fascinated with the Romans and Greeks. They were the epitome of what western civilization wanted to be and what it still strives to be (which is rather funny when you think about it but it is the perception).

But the Romans didn't create and spread the industrial age/system that will accelerate the growth of civilization and transition it to the modern economy we have today eh?

Well... lets take a look at the list.

1) British Empire... too young.

2) Roman Empire... not counting the Byzantines, it doesn't really work.

3) Spanish Empire... again too young, and largely influenced by others.

4) USA... Also, too young... with the one caveat being that the "American" way of life does seem to be permiating across the world in was even the British Empire didn't when they actually OWNED most of the world.   Not yet... If the USA stays on top for a while more though... all culture may be a hybrid of US culture.

5)  Islamic Empires/Dynasties... Maybe... they did di a lot, but a lot of it didn't end up working well... a lot of stuff having to be rediscovered.

Those off the Board.

1) China... too inturned on themselves.

2) Greece... Alexander the Great... did do a lot.  Still... doesn't seem like enough.  They influenced the Romans... but the romans did all the real legwork.

3) Mongol Empire.  The largest land empire in the world... and debatibly the biggest in the world. 

4) Akkadians, Precursors to Bablyon and pretty much the Islamic Empire.

5) Persian Empire... Huge Empire.  Powerful... etc.

I'm going Mongols.  Why?

1) Yuan Dynasty.

2) Mughal Empire

3) They caused a crapload of destruction where they came.  This was greatly infuential... in the demography greatly changed... and you could definitly say your country wasn't the same if the Mongolians came in.

4) The Mongols lead to the rise of Moscow, and effected why Russian history ended up.

5) Greatly expanded europes knowledge of the world, which lead to colonilization and trips like Columbus.

Yes but that industrial revolution didn't come without numerous moral consequences, inhumane treatment, socioeconomic distinctions, environmental deterioration, and exploitation of non-industrialized countries.  Personally I'd say the communications revolution of the past 50 years has been far more important and beneficial than the industrial revolution as a whole. 

Romans.

They martyred Jesus, and also started the Catholic religion.
They developed roads and advanced transportation.
They developed banking and credit.
They advanced military technique far beyond anything before them.

Those would be the ones off the top of my head. If I looked it up, I am sure I could find dozens more as great as these.