I'm sure there are more I'm forgetting, but here's what comes to mind:
- Birdemic
- Samurai Cop
- Sharkboy and Lavagirl
Special emphasis on Sharkboy and Lavagirl. I don't see enough people talking about this one. It really sucks you in, and it feels impossible to stop watching.
Oh man I loved Phantasm. I was blown away when I found out they made more than one.