OK, I know you tried an FPS. But Borderlands is a lot of fun. I will agree with you, FarCry 2 had some problems. But Borderlands is absolutely awesome! The shooting is fun, the RPG elements are intriguing. The leveling does not feel like grinding at all. It can get really hard, but you can always preserver with just some more leveling and side missions. Its only real problem is the driving is pretty bad (except one of your cars gets a rocket launcher!!), and some parts of the RPG are not up to snuff. It is more like an FPS Diablo.
RTS, a lot of options. People list off a lot of stuff, but my favorites...
-Warcraft 3 (has RPG in it, very good RTS. Storyline is amazing and long. Keeps you coming. Not PC intensive, but doesn't look horrible.
-Both StarCraft 1 and 2 (they are different but close enough for comfort. I'd take 2 anyday though, RPG in 2)
-Age of Empires 3 (this game is a lot of fun, but its story isn't amazing. RPG elements in it though. Skirmishes are a lot of fun. The armies can be absolutely huge though)
-Company of Heros (I haven't played it much, but it is fun from what I've tried. Has a huge fanbase so they gotta be doing something right.
-Command and Conquer 3: Tiberium Wars (Fun, shnazy, actiony. I like it.)
Just sayin', try the Civilization games or their style. They really pay off time wise, last you forever, and are sort of RPG-esque.
PS, don't get a Final Fantasy game, there are too many other options to go with that gelatinous glob.