Guilty-pleasure Sci-fi Movies

I was reading this list of the 50 greatest sci-fi movies of the last 50 years, and it was all fairly predictable. There’s only a couple that I’d disagree with, but there were a few that would have made the list in place of them if I were compiling it myself, and I realised my additions were less mainstream or less critically acclaimed than were on there.

What guilty-pleasure sci-fi movies would you recommend?

For starters, ones I’ve watched a bunch of times would be:

Dredd (2012)

Pandorum (2009)

Lockout (2012)

Monsters (2010)