Biggest problem with the S.T.A.L.K.E.R. series? That Shadow of Chernobyl was buggy to the point of unplayability. Call of Pripyat has been pretty good so far, though.
Biggest problem with the Halo series? That I don't have my own Warthog. I don't play online much, only co-op with my brother or a friend, even some split-screen action once in a while, and I've read some of the expanded universe, so I probably get more out of the story for it.
Biggest problem with Half-Life/Portal/Valve? The fanboys. I find Valve fanboys to be the most obnoxious ones I've ever come across, second only to some of the anime fans around where I live.
Biggest problem with the Halo series? That I don't have my own Warthog. I don't play online much, only co-op with my brother or a friend, even some split-screen action once in a while, and I've read some of the expanded universe, so I probably get more out of the story for it.
Biggest problem with Half-Life/Portal/Valve? The fanboys. I find Valve fanboys to be the most obnoxious ones I've ever come across, second only to some of the anime fans around where I live.