Ranul Keru is a gay Trill.
Kent Norel in Titan is IIRC, gay too. (human)
there was a lesbian in a TNG novel called 'The Best and the Brightest'. the first one.
T'Prynn in Vanguard is a lesbian Vulcan
there's a pair of gay Klingons mentioned in IKS Gorkon. one's more accurately bisexual since he's married. (gay affair)