I voted Assassins Creed because it had the greatest jump in awesomeness from the first to the second. First game was quite meh, second was awesome. Whereas Uncharted 1 was great to start with, so even though Uncharted 2 was amazing, it wasn't as big an improvement as what Assassins Creed made from 1 to 2.

The last choice.  Of the games on the list that I have played, I either enjoyed the first as much as the second (Uncharted) or enjoyed the first more than the second (Mass Effect).

Read my review of why the last choice wins! 

I would say Assassin's Creed 2. The First game was boring where-as the second was brilliant :D

i loved AC1 idk the hate it gets but whatever. Killzone 2 should be up there its the greatest sequel and such a huge jump from killzone.

I never played KZ1 and KZ2 was still a big dissapointment for me so I didn't put it in the list..

Killzone 2 or Red Steel 2. Can't decide.

I'd probably go with KZ 2.

ioi 2, and also killzone 2

Assassins Creed II, improved too much over the first one i was amazed.

Yeah. Leaving Killzone and Red Steel out of this poll is pretty peculiar.

From that list it has to be AC2. But out of any series probably Killzone 2. It went from a pretty average shooter to AAA.

ME, BC and UC were all great games anyways but AC1 was just good.

CoD4 is one of the best games ever and MW2 is mediocre. It gets my vote for most disappointing sequel.