I did not expect to like this nearly as much as I did, but although Alien vs. Predator is profoundly stupid, it is also pretty damn fun. The sets and camerawork stand out, the action sequences are snappy and clear (okay, yes, that second one is a low bar to clear), and despite being made in an era of widespread terrible CGI, the special effects here aren't cheesy at all. Only the premise is cheesy.
If the movie Alien and the movie Predator didn't exist, this would be considered a solid but unmemorable action movie. If it was simply about a generic extraterrestrial monster and a generic killing-machine monster, the movie wouldn't be changed at all, and nobody would hate it.