All in all, Dante's Inferno is good. Not great, but good. There are a few things technically wrong with it and it certainly doesn't win points for originality, but it's good fun all the same. It's just a bit difficult to recommend it with all the similar titles floating around right now. Darksiders offers a more open world, more depth in the RPG elements and better puzzling, Bayonetta has better combat and is just straight-up more fun and GoW III is just round the corner for PS3 owners.
You should buy this if you're either a) an Xbox 360 owner who wants GoW III but can't get it, b) someone who wants to like Clive Barker or c) someone just can't get enough of the hacking and the slashing. Or maybe if you're a goth.