Snakes On a MutherFuckin' Plane!
It delivers what it promises. Picture the top 5 places on your body you wouldn't want to get repeatedly bitten by a snake. In this film, people get bitten in all of them. And then some.
This is a signifigant film if only because it is the first film to become a cult classic months before its actual release. I would venture that it is also the first film ever to have been influenced, at least to this extent, by the fans while the film was still being made.

See also: "Snakes on a Train" and "Snakes on Claire Danes"