I grew up watching original Piranha movie. Own thedvd& still watch it sometimes. The closeups of the attacking piranha are hillarious. I flyfish, so every now and then I can enjoy A River Runs Through It. My old school favorite has to be The Incredible Mr. Limpet. Don Knotts was a rockstar. In Austin Powers "...sharks with laser beams attached to their friggin heads..." and the nod to "ill-tempered seabass" still crack me up. I also used to like that movie Orca, which really just tried to be a killer whale version of Jaws.
We're gonna need a bigger tank.