a few singers that come to mind are:
kele okereke of bloc party. their debut album was one of the strongest releases i've heard in quite some time; and when i found out that their lead singer was gay, i loved them even more. it put a whole new twist to their songs for me. their track, the prayer (off their second album), is an excellent song to lift to.
jonsi birgisson of sigur ros. i doubt the majority of people on this site would have an ear for this icelandic band, but they make beautiful music and jonsi is openly gay, which is always a good thing.
brian molko of placebo is openly bisexual, but he's so cute that he should be included. placebo crafts great music, and they recently did a cover of kate bush's, running up that hill, that just memorizes me more than the original (although tori amos did come pretty damn close).
stephen merrit of the magnetic fileds and future bible heros (among other numerous side projects). he has to be one of the most creative lyricists i've come across; he's just damn funny. not the best looking man in the world, but his art is beautiful.
jay brannan from the movie, shortbus. he actually composes and performs his own songs( 'housewife' is a favorite) and is phenominally cute to boot. he looks good naked too (really, you should watch the movie. words fail me. then you can tell me what the ending was all about because i still don't really get it.)
and of course, bob mould, originally of husker du, then sugar, and now solo artist. he was the first artist who taught me that not all gay men have shitty taste in music. i've drawn a great deal of comfort from his works over the years. go bob go. you still rock.
there are a lot more out there, but these are the ones that are off the top of my head.