Torchlight

[sycld]

...will be declared one of the sleeper indie hits of 2009, no doubt about it.

Essentially it's an ARPG clone closer to Fate in scope than a giant behemoth like Diablo III will be (and its $15-$20 price tag reflects this), but it is probably otherwise the best Diablo clone to come out ever since Diablo II. It's hard to explain why beyond the fact that it feels balanced, polished, and with enough to keep a gamer hooked.

In addition, TorchED will be released, which will allow for unlimited modding potential.

One significant feature which is lacking is multiplayer capability, so players looking for that will be extremely disappointed. However, an MMO is going to be released in the far future based on Torchlight, but that is at least a couple of years off.

At least give demo a whirl. You can get it off Steam and possibly other direct download services like Impulse. It might at least temporarily sate your appetite while you're waiting for Diablo III...

Oh, and finally it was developed by Runic Games, which includes many members from the team that made Diablo II.