Yes, Star Wars changed a generation, but going back to watch them now and they aren't what I'd term a 'sci-fi war movie'. Sci-fi, you bet. War, in parts, but on a grand, epic scale often used as a backdrop. Yes, Jedi had a lot of war in it, but as a whole, I wouldn't term the series as war-based.
Aliens was all war (skirmish-level). Starship Troopers was, while not Heinlein's book, a good tongue-in-cheek sci-fi war flick. Parts of Dune would qualify. Transformers (the cartoon movie) was a good war movie, for a cartoon.
What about TV series? Space: Above & Beyond, Battlestar Galactica, Starship Troopers: Roughnecks (another cartoon) all ring true.