I think Hostel: Part II is one of those rare sequels that is actually better than its predecessor. It takes what worked fine in the original and also adds new interesting ideas (we get to see the POV from the organisation), thus bringing it to perfection. I think the concept also works much better with female protagonists.
I didn't actually like Hostel very much on first viewing. Maybe it was because I hated the guys or maybe the focus of the film... I'm not sure. However when I saw Hostel 2, I immediately fell in love. Its one of those extremely rare sequels.
Due to my love for 2, I have rewatched the first a few times. I like it much better than I did, but it's still in a different league.
IMO it happens a lot; the sequel a lot better than the original! They work out the kinks and get better people to produce it! Not my genre, but something makes you watch when it come on; at least for a little while! These movies are so bizarre to me; "Saw, Hostel, and Cube" series! ;-)
I found myself fast forwarding alot through the first one. Wasn't a big fan of the guys, but I was more drawn to the girls (I thought all the characters were interesting) in the sequel.
I liked it a lot more than the original. I felt this one had better acting and a much better story line and twist. The third Hostel was horrible though.