I’m aware of the seeming contradiction CountZero. The reason I don’t count myself as a sci fi fan is that I dislike so many of the ‘classics’, most of which have been mentioned on this thread.
For example I understand that many people have real love for Blade Runner, and I respect that. I found it a bit dull. Loads of people love the Matrix, and I’m happy that they enjoy it, but I thought it was unbelievably trite with laughable fight scenes. 2001 is supposed to be this all time great movie but it did nothing for me. I liked Star Wars (whatever the original one is called now) when I was 12, but not when rewatching it. Alien is an ok movie, but I’ve never understood all the fuss. If I was going to rewatch a Ridley Scott film it would be Thelma and Louise.
I find it a genuinely pleasant surprise when I find a sci-fi movie I like (someone mentioned Silent Running earlier, that’s another good one). Westerns though, I love westerns. I could – and sometimes do – watch those all day.