Alone in the Dark is hugely under-rated in my eyes. And along with The Hidden, I'd say it was Jack Sholder's best film. Great cast too - Jack Palance, Martin Landau, Donald Pleasence, Dwight Schultz and Erlandt van Lidth. A must see for 80's slasher fans.
Funhouse is an enjoyable weird little slasher flick, and in my eyes likely Tobe Hooper's most under-appreciated film.
Many of the earliest Cronenberg horror films seem to be largely forgotten these days, apart than Scanners. But The Brood and Shivers still stand up to this day as great examples of low budget horror.
For years Near Dark was largely forgotten by all but a handful of horror fans, but it seems to have had a bit of a second wind after it finally hit dvd a few years back.
Peeping Tom, which hit the same year as Hitchcock's Psycho, and which I personally still think is the better film of the two, seems to have fallen between the cracks in recent years, despite quite a bit of controversy when it was originally released. In fact so much controversy that it basically killed Powell's career dead in the water, he was blacklisted in England and many foreign opportunities for him also dried up, whereas Hitchcock seemed to get away with Psycho with much less scorn and outrage. Peeping Tom was basically seen as the Henry: Portrait of a Serial Killer of it's day, even though you look at the film now and, though still excellent, it seems somewhat tame. But I guess the world has changed a lot in nearly 50 years...