One of my personal favorites has always been C.H.U.D. (cannibalistic humanoid underground dwellers). Critics hated it and so did most people, but I really liked it in all it's awfullness (It's just so bad it kinda makes it good).
Another on I can always watch is Godzilla, the one with Mathew Broderick. It's stupid but it's entertaining as long as you leave your brain behind - far behind.
I think Soldier with Kurt Russell was pretty under rated. It got pretty bad reviews and a lot of people didn't seem to get it either, plus it moves along slooowwly but I think it's a great story and that makes up for a lot.
There's probably several more I could come up with if I tried to care what other people thought about the things I like.