These are possibly two of my favorite gay-themed movies I've seen, at least the best I've seen in a long time. Mulligans was interesting enough, but the acting was pretty terrible in parts, and the script made me roll my eyes sometimes, so it does not make the cut. :-)
Torch Song Trilogy - Not as over-the-top as I expected. Pretty dern gay, but in a very human, down-to-earth way. I really liked the simplicity of it and had no idea such a frank, heartfelt portrayal existed in the eighties. It's still quite relevant today, particularly for those coming from conservatively religious families. Some prominent themes of the movie include a gay man's strained relationship with his religious mother, the desire to settle down with a partner and build a life together, adoption, mixed-orientation marriage, and desire/need(-iness) for acceptance. It's rated R for language and subject matter.
Save Me! - A young, gay, drug-addicted man is sent to a Christian ministry called the "Genesis House" which focuses on a twelve-step program centered on the gospel of Jesus Christ to overcome homosexual inclinations and live according to God's word. Of all the gay-themed movies I've seen, this is probably the most balanced, complete exploration of ex-gay ministries so far and has a Christian-oriented resolution. Mind you, I still don't think it's going to change a lot of minds on the issues raised, but I really appreciate how it doesn't demonize or even necessarily preach but explores the very human motives for the decisions people make and the attitudes they adopt. It's not rated but would be R for subject matter, for some language which is appropriate to the characters (not exaggerated or especially pervasive and gets milder), and for drug abuse and a sex scene between men in the beginning which is meant to establish a dichotomy of lifestyles and is, despite only showing dim, partial butt shots, fairly graphic. You could skip the opening scene without missing much if you're concerned about that content.