Of so, the story isn't anything special, it is however told brilliantly. The first thing that stands out is the team, they are a diverse mix of soldiers, all bringing something different to the team and they're all strong enough that Arnie doesn't obscure them with his own character. There is an excellent camaraderie between the team that really comes across and gives them meaning once things hit the fan.
The next big point is the pacing, things get going pretty much immediately, the team enter the jungle and you see the team in action and you get a feel for how well they operate together. You also get some insight into the thing that hunts them. The film quickly establishes the team as a group of absolute badasses before picking them off one by one.
It's not non-stop action, the film knows when to let the foot off the pedal and build some tension, there's a few moments when they're waiting that work the moment. Layer onto that an excellent alien and you have a great action film. The predator is a cool opponent, he's tough and smart and has some cool toys. It also has some of the most quotable lines ever :-)
The final icing on the cake is the music, it works at every moment from the title credits all the way through to the end. This film was made before the advent of mass CG, but is still a visual treat and I would argue better for it. For me this isn't just one of Arnie's best films, it's one of the top action films ever made.