I'm assuming we're talking about worst mainstream movies here, but I've got three indies from right here in my own backyard of Hamilton. There's a shoebox company here called CJ Productions who sold me two of the worst b horror flicks I've ever seen. I was happy because I love Cheepnis.

Vampire Dentist is about a vampire who opens up an all night dental clinic to feed off his patients. He also does his landlord to avoid paying rent on his office.

Sharp Teeth is the better of the two. In this one the steel mills have polluted the bay with radioactive waste. The carp mutate and begin to eat people.

The absolute worst I've ever seen actually made it onto imdb. Cannibal Rollerbabes features slutty chicks on old school rollerskates who travel the wastelands of Peterborough in dune buggies looking for people to eat. A friend introduced me to Nicole, who played Bumper. We dated for a short while after it was shot and she brought a copy of it over. Horrible. Wish I still had it. It also stars psychic Playboy playmate and baby-abductor Lisa Heughan.