dunno why everyone is asking for KZ2 - all the other sequels are within the same generation. different generation jumps is soo not a fair comparision.

i voted uncharted 1 - 2 because A) only games i've played on the list and B) i loved how many improvements when into the series. the stealth gameplay especially impressed me.

Uncharted 2. An honourable mention goes to AC2.

so far Uncharted 1 to 2 is winning

Okay so U1-2 won

May have said Assassin's Creed 1 to 2, but only played 1 and it was utter tosh! Good setting though. Heard great things about AC2. I went with Uncharted, Uncharted 2 was simply brilliant.

So this means Uncharted 1 ain't worth getting then. Good to know.

In my opinion Bad Company is the most improved though. Assassin's Creed is 2nd.

Assassin's Creed II is the most improved because AC 1 was quite bad and AC II fixed a lot of the problems and that's what made AC II really shine out.

IMO not so much Bad Company because though Online is far better in Bad Company 2 than 1 but both games have crap single player campaigns.

Uncharted and Mass Effect were both great new IPs to start out and both sequels are Highly Acclaimed Titles so they are improved sequels, but they did not jump from "mediocre game to outstanding impressive game" like AC II did.

COD4 to MW2 went backwards so I don't see why that's even an option.

U2 by far. With X amount of GOTY awards in the bag too.

gears 2!

(I voted mass effect 2 :D)

Mass Effect for me, ME 1 was a great game, but ME 2 is the best gaming experience I have had since TLoZ:OoT.