I loved the first Star Wars (I'm not going to figure out Lucas's backtrack numbering) Liked the second one better. Hated the 3rd one. Nothing like making fun of your own series right? Chewbacca doing the Tarzan yell? Stormtroopers that couldn't hit the ground with their guns if they wanted to. End of that for me. Lost interest in it almost completely and haven't seen anything but snippets since.
Aliens. Watched it and loved it. Watched most of the series but not all. Got a little goofy with the one that had a half human/alien that chomped off a guys head. My favorite thing in the movie was the human forklift. Wish I had that.
Prometheus was just bad. Boring. The only interesting actors was Cherise (?) and the blond robot guy. Yes run in a straight line, exactly in the same path as a giant ship is crashing. Doesn't it make sense to run at a right angle? No? Well then, that is prometheus.
Bladerunner. Great first film. Was bored by the second. Wasted the opportunity to be interesting.
I don't love a series just because it is one. Individual movies have to stand on their own.