If you're into games like God of War, the PS2 CV's & Rygar, and Ninja Gaiden on the Xbox, then you'll probably like DMC as well. The first one is my favorite of the three. The learning curve is just right, level design and atmosphere are top notch, and the story is interesting. I rented DMC2 but didn't like it as much. It didn't seem to have the atmosphere or difficulty balance of the first one. The enemies aren't nearly as cool, as you're fighting things like apes and possessed helicopters instead of the demons from the first one.
DMC3 is...really, really hard. I tend to suck at 3D games, but I've beaten enough of them that I'm not sure that's the problem. I can't beat the third level on Normal difficulty without spamming items, even after replaying the first two missions several times to level up my character. And I hate playing on Easy because it's made to feel like an insult in this series. But other than the difficulty, DMC3 brought back much of what was good in the first DMC.