I actually found the Starship Troopers movie to be quite good, even though it barely had a passing resemblence to the book. Basically, just think of them as two different stories and it's all good. The biggest problem with the movie is that it didn't do anything to dispel the untrue conspiracy that Heinlein was a fascist. I mean, they had the military guys wearing nazi-inspired uniforms.
What's better than fresh-faced teenagers getting ripped apart by bugs?