I was in HCM City in April and can recommend Q Bar in District 1 (under the opera building). It's mixed but has a good feeling and plenty of gays. You may want to start at Vila (which is close by) and then head to Q bar. Apocalypse Now, which used to be the place to go, is now pretty much a disappointment. Take a look at
www.utopia-asia.com for some more ideas.