If you really like micromanagement Crusader Kings 2 is great. A bit pricey with all the DLC, though, but we're talking real DLC, the kind that actually changes game mechanics. I'd pick up the whole package during the Summer Sale or something.

http://www.thehunter.com/

http://photo.thehunter.com/2e17e778e33bd50db4c513f464d0adedb49d38d0.jpg

Binding of Isaac is a great time killer for however long or short you like.

I found this neat game the other day called Perspective.

http://www.seewithperspective.com/

http://www.kongregate.com/games/garin/monsters-den-book-of-dread

Probably the best flash game I've ever played

It's sort of a turn based dungeon crawler/RPG hybrid.

Kingdom Hearts 2 or any of the pokemon games :)

Binding of Issac 4ever

Honestly, if you are into RPG's that are not all about "eye candy" you will find the Geneforge games to be incredibly rewarding and fun. Geneforge 2 in particular was one of my favorite games of all time.

I still play today just to create something different with my characters. The game's endings are based on your character choices throughout the game so it can be a different ending almost every time you win the game.

http://www.spiderwebsoftware.com/geneforge2/

Older stronghold games are really fun (crusader and what not)

any fallout game
any fable game (2 and 3 are not nearly as good as tlc)

Ratz instagib is great fun