First of all I can't believe that the two best games this year (and this whole gen so far for me) came out one week apart (Demon's Souls and Uncharted 2). I bought my PS3 in Auguest 2008 and my 360 on Jan 09 and this gen didn't start for me until this October.
A lot of games (espeacily PS3 exclusive) had a lot of hype but non of them delivered. They were fun games but non meet their expectation (KZ2, MGS4 and also the first Uncharted) however Uncharted 2 is one of the few games that had massive hype and totaly delivered for me. I said before that the first Uncharted was a good game but I wouldn't spend more than $30 on it, for U2 however I would happliy spend $60 for the single player alone. It was just amazing and I don't know how did ND did it and when you include the Multiplayer and Coop DAMN !!
Demon's Souls is by far the biggest surprise this gen. A truly amazing RPG and by far the best I have ever played. It had a revolutionary online system and I mean it. I could go own and own about how From Software crafted this masterpiece.
In short Demon's Souls is the best game this year (and this gen) with Uncharted 2 right up it's ass that I wan't to say a tie 
Sorry for the long post just wanted to finaly put it out there.
