Didn't really write out my post earlier but here goes:
Best RPG I ever played to date is
Dark Souls.
- It has an incredible story, which is really novel in it's presentation. Without spoiling much, the story is less of a movie and more of an active role you play.
- It has an Oldschool RPG style where you can really play out as the character you want to be. You can truly roleplay a character....like really write them out and their goals, motivations, skills, and etc, and you can level up your character and find items in the game that will allow you to always play out that role.
- The game also doesn't limit you to playing one specific way. Every approach is viable, so the game is really about how your character progressed, and what choices they made.
- Beautifully crafted world. I haven't seen a game world and inhabitants be so beautiful and diverse in a really long time. You'll always be surprised in the game by what you encounter, and the eye candy will never dissapoint. (well as long as you dont watch any guides, walkthroughs, or wikis but if you do whose fault is that?

).
- Actual consequences in questing. What you do in the game....matters, and making different decisions can dramatically affect how the game plays out. It's really cool.
Tag all of that onto what has to be the most fun, deep and diverse, 3rd person melee medieval combat system crafted to date, and you have an amazing game.
I'm really excited for the PC release with all the new content! It's gonna be great!
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Demon Souls takes a close second for me. It's like its successor, Dark Souls, but the atmosphere is better in Demon's, while the combat is not as deep as Dark Souls. Story is incredible in both games though.
Third is
Legend of Grimrock. I never played a "hallway" type RPG before, so Grimrock was an impulse purchase...but MAN it's fun! Cool puzzles, difficult game, lots of exploration, just awesome.
There are others, but those three stand out at the top for me right now.