Starship Troopers was the biggest disappointment I've ever seen on the big screen. It really had nothing to do with the book except reusing a few character names.
Luckily. Verhoeven made clear his opinion of Heinlein's book. I think it's an underrated movie, quite funny if you get the intention. All troopers look like Beverly Hills, 90210/ Melrose Place characters and almost everyone dies.
It's hard to choose the worst movies I've ever seen; too many candidates. Any with Freddy Kruger
plus some 'action' films and silly comedies whose titles I forgot. I hate Grey's Anatomy, if that helps.