One of them is Cannibal! The Musical (1993), an awesomely awful film about the pioneering raw foodist Alferd Packer, directed by (and starring) Trey Parker, also starring Matt Stone. You can scroll down to watch it in entirety right here.
Trey and Matt, of course, are the same guys behind South Park and the hit Broadway musical, The Book of Mormon. They've come a long way in the 20 years since "Cannibal," and for me, that's part of what makes it so fun to re-watch now—it's so very, "Hey guys, let's put on a show!" Snip from the Troma tease:
"Cannibal" is the true story of the only person convicted of cannibalism in America -- Alferd Packer. The sole survivor of an ill-fated trip to the Colorado Territory, he tells his side of the harrowing tale to news reporter Polly Prye as he awaits his execution. And his story goes like this: While searching for gold and love in the Colorado Territory, he and his companions lost their way and resorted to unthinkable horrors, including toe-tapping songs! Packer and his five wacky mining buddies sing and dance their ways into your heart...and then take a bite out of it! Cannibal! The Musical is Oklahoma meets Bloodsucking Freaks. Brought to you by the Troma Team and Trey Parker -- the Rogers and Hammerstein of Horror!
"Cannibal" later became a live stage play, starting in New York, and moving on to a number of other cities. My friend Jason McHugh oversaw the live touring production, played in some of the stage performances, and wrote a book about it all in 2011. Good times.
Trailer above, full length film via Troma is below. The official "Cannibal" fan-site is here. Amazon has the DVD from Troma, which includes a "Drunken Director's Commentary" in which Parker, Stone, and cast members get drunk and talk about the film while watching the film. Below, watch it in entirety via YouTube. There's a Troma promo that runs up to about 2 minutes 20 seconds in.