Finally! A movie that's worthy of being a sequel to the original Arnie Predator. Forget those lame AVP movies, this was the film that should have been made. It only took some 20 odd years for a film maker to get it into their head and say "I'll make a movie that fans of the original would enjoy".
In my mind, this is the complimentary piece to Predator, as Aliens was to Alien. You give the audience more of what made the first one great, and you expand on that.
What I enjoyed most was the continuity. And by that I mean the references to Arnold's encounter, the music, the tone, it actually "felt" like a follow up, not just another Predator movie. Hell, even the acting wasn't bad, and the movie was filled with great one liners ("Die, space faggot!" lol). I don't know about other people, but I found those things important to have for the overall experience.
The predators themselves were great, I loved the new looks, they were looking fierce as ever, and that there were several different types of them. I didn't know how well the other creatures would go over, but they ended up being pretty cool, too.
I was pleasantly surprised that Adrien Brody was decent as a Black Ops badass. I didn't think he'd be able to convince me, but he did well enough. His relationship with Alice Braga's Isabel character was believable.
So far I've enjoyed this and Toy Story 3 the most this summer. There may be hope, yet.