I've seen and would personally recommend Juste une Question d'Amour and Sommersturm. Posters have also mentioned C.R.A.Z.Y which is also very good as well. These all have good storylines and much better acting than most gay-themed films that I've seen. Funnily enough they're all foreign films as well. I found Latter Days to have an interesting storyline but I found the acting a bit bad/off-putting in some parts..