I wasn't that impressed with Portal, it was too short, and not much of a challenge so for me it wasn't very rewarding completing that game.
The only new game I like is L4d, mainly because versus mode is so much fun, especialy with people you know.
L4d must be the only game iv bought in over a year, most the games out now just seem generic. One of the biggest problems is that game developers want games to be accessable to newcomers, often making games easier to play (like adding shitty re-generating health to evry game). But almost evry developer wants thier game to be accessable to evryone, while at the same time taking ideas from pre-existing games. Evrything that has been released lately seemes the same, or has this feeling that this has been done before and been done better before. On top of that no developer wants to take a risk on anything. It seemes to me as if evrything that has been release in the last coupple feels generic.