I thought Starship Troopers, in novel form, was pretty good and serves as more-or-less definitive Heinlein. It broaches a few ideas, but doesn't delve into them too deeply, and isn't too cerebral overall. It is, after all, a military-action story. Heinlein's ideas about violence and its role in human culture are interesting, even if they may seem objectionable to some.
I loved the film when it first came out... but then again, I was fourteen years old. As far as sci-fi shoot-em-ups go, it's great. It is not a serious film, and not a very good adaptation of the novel. I remember having the companion guidebook to the film, which had a lot of conceptual artwork and making-of articles. It went pretty deeply into the differences between the novel and the film, and the reasoning behind them. I'm sure you could pick that book up for loose change on Amazon if you're interested.
As far as fascism goes, I thought the juxtaposition of hive-mind military species (the bugs) and the measures taken by a species forced into martial law in its fight for survivial (the humans) was interesting. I'm sure I read way too much into it, but subtext is subtext, whether or not it's intentional.