The Mask holds the distinction as one of the best overlooked gems I've ever seen.
No, I'm not talking about the wet-fart of a '90's Jim Carrey blockbuster that spawned a braying jackass of a sequel with Jamie whatisface. I'm riffing on the 1961 Canadian horror flick directed by Julian Roffman. Until some very smart video company gives Roffman's finest movie the grand digital treatment, a 3D copy can be tracked down on VHS from Rhino Home Video (tho' I think it's out of print; get thee to Ebay, citizens).
It's a stark Twilight Zone-ish setup about an ancient Etruscan mask that, when worn, induces hallucinations of the most phantasmagoric kind. College professor Allen Barnes (Paul Stevens) comes into possession of the artifact and discovers to his helpless dismay that in addition to sending its wearer on one epic bum trip, the mask induces uncontrollable homicidal urges.
Roffman constructs a well-paced thriller that makes good ambient use of its spare black-and-white photography. Until the hallucinations start.
Roffman shoots the hallucinations in 3D. And when a character is inexoribly called by the lure of the mask to put on the creepy headgear, the soundtrack intones, "Put the mask...on...NOW!" That's, of course, the cue for the viewer to put his or her 3D glasses on. The surreal visions that ensue, like the rest of the movie, make real gold out of a low budget.
It sounds cheesy as hell, but it's low-key, tensely directed, well-acted by a cast of relative unknowns, and really, really creepy. In look (not subject matter), it brings to mind the 1962 low-budget classic, Carnival of Souls.
Roffman's only other film of note was a 1978 action flick called The Glove, with a great trash film cast--John Saxon, Rosey Grier, and Nicholas Worth, among the ensemble. It's a shame the director never crafted any other horror movies. The Mask is a real overlooked jewel.