Disgaea 4 does have tons of contents. Platinum can take almost 200 hours, more if you're not focusing into getting it. Gearing your characters with the best equips also take considerable amounts of hours. It's pretty crazy when it comes to contents.
There is a board for RPG, you know: http://www.gamefaqs.com/boards/220-rpgs-everything-else
Deus Ex & Alpha Protocol for Deus Ex alone. AP is a... bonus.
What this guy and other similar entries have been. Deus Ex is a really good game, if a bit odd with the boss fights (they were outsourced to another team, I believe,) and Alpha Protocol is a good game if you approach it as an RPG similar to Mass Effect 1, or the original Deus Ex. You pick up a gun, and you have no training in said gun use, and you won't be able to hit almost anything with it - just like a real person would with no real experience handling said gun.