Obscureness based on IMDb votes "( )". I only included movies, no video or TV. My ten most obscure are:
1. Blood Rites 2003 (23)
2. Siege of Evil 2005 (30)
3. Here Comes a Vampire 1990 (70)
4. Black Mamba 1974 (89)
5. Kung Fu Fever 1979 (94)
6. Texas Payback 1995 (102)
7. The Dark Side 1987 (108)
8. Top Cop 1990 (119)
9. Hell Hole 1978 (121)
10. Body Shop 2008 (126)
Out of those, I rented The Dark Side and Top Cop back in VHS days. Body Shop is a surprisingly solid and violent C-Movie, starring William Smith and Robert Z'Dar.
I was thinking it's probably AFTER LAST SEASON, but it has 8.6K votes. It's still one of the rarest movies I own, because I have an actual DVD of it. Not sure how many discs were made, but I could sell my copy for $300 on Ebay if I wanted to.
I imagine some of the movies on those 50 DVD set collections I have would be the most obscure, but I don't think I'd look them all up.
I have Mystery of the Leaping Fish on vhs
CHAMPION KILLER (1994) (48)
also probably the worst made film I've seen, although there's some hilarity to be had. found in a pound shop iirc
edit, ok here's my old 'review':
"not sure how or why I ended up getting this on dvd but it has stayed with me as THE worst movie I've ever seen. incredible jawdropping ineptness from another dimension of crap, multiplied by awful, to the power of not very good actually."
don't think anything else I own would have under a few hundred ratings
RIDE THE HIGH WIND and SHANGANI PATROL are probably the most obscure films I have in my collection together with most of the apartheid era films which weren't released overseas in their day.