As I mention earlier, M/M Romance is a harbor for friendship-romance, romance that starts and depends on friendship to thrive.
A favorite sub-genre here is the M/M Romance based in the sports world, which focuses on a relationship between two teammates or, in the case of Avon Gale's Power Play, two coaches.
Like high school settings for teen dramas, sports provide instant useful fiction criteria: the characters have jobs; they must work together (to score points or to get the team to score points), they are members of a structured society which society also provides moments of tension and drama.
Power Play has the additional pleasure of giving us the Darcy-Bingley combo, a coach with a stern, introverted approach to the world alongside an assistant coach with a friendly, blithe way of embracing the world.
I actually prefer sports romance to doctor-hospital romance. Doctor-hospital romances always seem to descend into soap opera (see Saving Hope). Sports romances don't always end with a Superbowl ring or Stanley Cup or equivalent but at least the characters have something specific to strive for (other than falling in love, of course).