A few months ago I actually just found out about the original game (a Diablo clone). I don't know how I missed it years ago when it came out, but somehow I did. It is a really good game, and I can actually play it on my netbook (it has a "netbook mode"). Of course things are really small on the netbook, but the fact that I can actually play on it is a bonus. You can just download the original for about ten bucks online.
I recently read there will be a Torchlight II that will come out around December 2011, with a multiplayer feature and more above ground quests, yay! Look forward to it.