These are from the Gaydemon Directory index and should be pretty inclusive of the various gay niches. Of course these go into mini and micro niche options as well, but that'd be a bit tedious to list! For example Foot Fetish can mini niche to socks, and then micro niche to white socks.

Armpits
Bareback
Bondage
CBT - cock ball torture
CFNM - clothed female, naked male
Cock Pumping
Cum Eating
Dildos, Sex Toys
Enemas
Fist Fucking
Foot Fetish
Latex, Rubber

Leather
Master & Slave
Medical Fetish
Piss, Watersports
Shaved Cocks
Skinheads
S&M
Smoking
Spanking
Tickling
Wrestling


Bisexual Porn
Crossdressing
Fucking, Anal Sex
Gay 4 Pay
Glory Holes
Group sex, Orgy
Interracial Sex

Live Sex, Webcams
Masturbation
Rimming
Rough sex, Sleaze
Sucking, Blowjobs
Voyeurs, Public sex

Cartoons
Erotic Stories
Hentai Cartoons

Morphed Images
Photography
Vintage Porn


Arab Men
Asian Men
Bears, Hairy Men
Black Men
Bodybuilders
British lads
Butts, Ass, Balls
Chubby
Cock Pictures
College, Frat boys
Hung men, Big cocks
Jocks, Athletes

Latino Men
Male Models, Celebs
Mature, Older men
Men in Suits
Muscle Men
Naked Hunks
Porn Stars
Straight Men, Amateur
Twinks, Gay boys
Uncut Men
Underwear
Uniforms, Military