1. Dark Souls
#1 easily, in fact this may be my favorite game of all time. I spent 120 hours on it over 3 and a half weeks and loved every second. If <a href="http://forums.namcobandaigames.eu/showthread.php?p=2331294">Dark Souls comes to PC</a>, I will absolutely S-Rank it again.
2. Dead Space 2
I played Dead Space 1 a week before Dead Space 2 to get prepared. I'd heard great things about the game and I'm really happy I put the effort in to play through both titles. Dead Space 2 had some really impressive moments and the game play was super fun. I decided to play through it on easy because I felt like replaying scenes when I died would kill the momentum.
3. Portal 2
I didn't really read much about Portal 2 prior to its release, so I was delighted to find out while playing that Stephen Merchant did the main character's voice acting. I can confidently say Portal 2 is the funniest game I've played. The co-op added a really a nice touch to the overall experience.
I spent 80 hours or so on a few different characters and worlds. I never got into Minecraft, because it seemed more of a sandbox and less like a game. Terraria's art style coupled with its more game-like elements drew me in when Minecraft could not.
5. Uncharted 3: Drake's Deception
More of what made Uncharted 2 a great experience. I felt like the first games jumped the shark a bit with the zombies (1st one) and blue people (2nd one), so I was really pleased at how they mixed up the story by adding a touch of paranormal while maintaining believe-ability (spiders, hallucinations).
Great environments, satisfying combat system, wonderful soundtrack, and incredible narration. These are just some of the reasons why Bastion is great.
Such an awesome magic system and great multiplayer support. The bugs were somewhat annoying, but the development team ironed them out pretty quickly. Magicka was my first Steam S-Rank, until all the damn DLC came out.
8. The Legend of Heroes: Trails in the Sky
Wonderful little RPG with its roots deep in the classic RPGs of old, the likes of which I haven't seen in a new title in a while.
9. Mortal Kombat
Great visuals, awesome fighting game engine, and a pretty neat single player story (although I doubt I'd ever play through it again). If the online offerings were tighter at launch, I'd probably still be playing the game.
10. L.A. Noire
I really have mixed feelings on this game. It was such an impressive offering, but in the end, it's just not a game that I can play as it was intended. I got so frustrated early on missing questions (truth, doubt, lie), that I ended up resorting to a guide for every interrogation. Even still, by playing it this way, I had a great experience with the game.