Well, if you haven't looked into it already, you could try Blades of Exile. Very retro stuff, circa Ultima 3 or so, and the graphics are old-fashioned. However, it's turn-based. Party of six, but you can go with less if you like. The three scenarios that come with it are mediocre, but there are a LOT of user mods for it, and those are all free. Should keep you occupied for awhile.
They just came out with Blades of Avernum, but I'd go with BoE because there are so many more scenarios for it. Find it at:
http://www.spidweb.com
You can download the game and try it for free. Buy it and they give you a code to unlock the whole thing.
Nightowl2