The original is good. You're right about the combat, but I found for the most part the pacing is really good. So the puzzle solving and exploration break up the combat nicely and vice versa. The art style was one thing that attracted me to the original. It's nice to play a game with some colour in it for once.
My only criticism of Darksiders is it seems to run out of steam at the end. The last dungeon is a bit of a let down and seemed to be a copypasta job in terms of level design (
you have to solve the same puzzle and mini boss fight 3 times). But the story is awesome and the last Boss fight and end cutscene set the tone for the sequel brilliantly.
Darksiders 2 seems to be getting good reviews all round at the moment. Total playing time is around 20 hours allegedly. The general consensus is they have expanded on everything from the original

ಠ_ಠ ... ლ(ಠ益ಠლ)