In terms of aspects, as opposed to genres:
Narrative: Now, narrative is more than simply the script before anyone gets confused but I'd have to say Red Dead Redemption gets my vote.
Presentation:God of War III. The game itself is a hack 'n' slash and not much more but the way everything is presented is awe-inspiring. The scale in particular.
Detail: Not graphical fiedlity, you must understand, but the amount of stuff happening in the world. Grand Theft Auto IV is unrivalled in my experience in this department.
Atmosphere: Condemned 2. Up until the last level a least (which I can forgive) this game was pant shittingly atmospheric. Demon's Souls is also a contender but I haven't played past the first level of it due it's nut-crushing difficulty so I felt it would be out of place.
Fun: Just Cause 2. I mean, c'mon, you can surf goddamn fighter jets while a mook flaps about suspended by a cable below it. It's not perfect, but my god is it entertaining.
Mutliplayer Awesomeness: I do indulge in mutliplayer from time to time and most of those times it is Battlefield: Bad Company 2. The game is robust, fun and has a strategic edge which I immediately preffered over Call of Duty. Sure, the PS3 servers have been wonky the past few weeks but that hasn't deterred me.
Non-Categorised Awesome: The Darkness. I just wanted to mention this game because of how good I found it. I understand not everyone will agree but in the three years since its release few games have compared to the feeling I got just playing this game. I don't even know what it is about it.
And finally...
The Metal Gear Is Now Over award for Plot I Can Sink My Teeth Into: Assassin's Creed, please give me more of your batshit insanity and conspiracies, I can't seem to get enough since I've polished off Metal Gear, Lost and The X-Files O____O