The Boys In The Band (1970) 12/12

The end.

People have asked in the comments which cast members did and didn't die of AIDS-related illnesses, so here's the list...

Kenneth Nelson (Michael): died from AIDS
Frederick Combs (Donald): died from AIDS
Cliff Gorman (Emory): died from leukemia, didn't have AIDS
Laurence Luckinbill (Hank): still alive
Keith Prentice (Larry): died from AIDS
Peter White (Alan): still alive
Reuben Greene (Bernard): still alive
Robert La Tourneaux (Cowboy/"Tex"): died from AIDS
Leonard Frey (Harold): died from AIDS

So while it's true, sadly, that over half the cast ended up dying of AIDS-related illnesses, any urban legends about "all the guys in this movie died from AIDS!" are indeed urban legends.