Knights of Honor is a more than decent strategy game that sucked quite a bit of time from me.

As for RPG'.. I have to admit to finally playing Morrowind (hey, I was bored, and it was only 10 bucks). It's a blast. After the initial "getting used to phase" , which took me about an hour and a half.
Fairly low end specs, for todays standards, with great eye candy to boot.