The SciFi Channel movies are great, the stupider the better.
All the shark movies - Sand Sharks that swim in the ground, Ice Sharks that swim in ice & snow, Ghost Shark that comes out of any water, even a bucket. Trailer Park Sharks. Santa Jaws. DinoShark. Ozark Sharks. Zombie Shark, Toxic Shark, hopped up on nuclear waste. Dam Sharks, building a giant dam out of human victims. MegaShark, taking a bite out of the Golden Gate bridge.
And let's not forget what may be the best of all, Sharktopus!
Mega Piranha - giant piranhas that eat naval ships and jump out of the water to explode when they land...
And Piranhaconda, Whalewolf, Pteracuda, Mega Python, Gatoroid, SuperGator, Cajun Redneck Gators, DinoCroc, RoboCroc, Crocosaurus, Lavalantulas...
Honorable mention to a true stinker, the Chinese production Croczilla - music by Dong Dongdong.