A good indie diablo-style action RPG is
Din's Curse. It takes the randomization to a whole new level, the towns are random, the people in the towns are random, the quests are random, and the dungeons are so random that I have rarely seen two that looked the same, let alone had the same number of levels. It also has mix-and-match classes. Got it a while back, and I definitely enjoy it more than Torchlight.
But the stand out feature is the dynamic nature of the gameplay. Basically, this game doesn't just give you quests and waits for you to do them, it gives you quests and if you don't do them quick enough there
are consequences. The town could be attacked by monsters, everyone could be killed, even your quest givers. If you don't kill a bad guy soon enough he could start an uprising in the dungeon, increasing the number of monsters to fight and changing which monster types appear on a certain level of the dungeon. You can actually
lose by having the town overrun with monsters. A boss monster could spawn
in town.
Sorry to go off topic like that, I do use Impulse for some of my games, and I'm hopeful that they won't be turned
completely into soulless corporate lackeys. However it is a possibility.