Old, kind of out-of-date, but the first one I ever saw>The BOYS IN THE BAND. Also LONGTIME COMPANION and PHILADELPHIA.
PRISCILLA, QUEEN OF THE DESERT, TO WONG FOO, and the French LA CAGE films are always fun.
(but get the FRENCH versions...not THE BIRDCAGE)
An interesting and moving film about a man transitioning from male to female, and the impact it has on his wife and kids>NORMAL.
BOYS DON'T CRY is good...sad, but good.
A really good British mini-series about lesbians in Victorian London>TIPPING THE VELVET.