-Dragon's Dogma
(Best real time action rpg I've ever seen with awesome miniboss and boss fights. Has some flaws, like companions never shutting up and no fast travel, but those can be overlooked.)
-Dark Souls
(Finally a really gritty rpg that's pretty challenging.)
-Disgaea 4
(Disgaea is awesome, no matter what.)
-Kingdoms of Amalur: Reckoning
(uninspired, forgettable characters and 'meh' story, but VERY awesome combat mechanics, level up system and customization.)
-Warhammer 40k: Space Marine
(Just about the most awesome hack and slash I've ever played.)
-Shadow of the Colossus
(Fighting HUGE monsters by climbing on them, plus the visuals...*drool*)
-LIMBO
(Such an awesome indie platformer.)
-Journey
(It's more an experience than a specific game, but still definitely worth it.)
-Assassin's Creed 1/2/3
(It wasn't for me, but I know that the games are really good.)
The games in this second list are either not that good, a niche game, or good but not 'must have' material:
-Skyrim
-Prototype
-Infamous
-God of war
-Dragon age 2
-Brutal legend
-Fallout 3 or fallout NV
-Heavy rain
-Final fantasy 13