Now I don't want to get on my soap box here, but it became pretty clear to me from the get go that I'd have to mention /r/LGBT. I've used Reddit for quite some time, and the simple fact is that the management of this subreddit is done in a very problematic fashion. I mean, this place went so far down the toilet that people migrated over to a rival community that better suited the desires of the LGBT people.
I recommend /r/ainbow over /r/LGBT any day of the week, but this place is still worth looking at from time to time to see if any news articles or stories are worth your attention. Again, I don't want to come across as a crusader for mah freedoms, but I genuinely believe that the way /r/LGBT is maintained is contrary to my desires of a decent subreddit.
For more info, feel free to Google 'Reddit LGBT subreddit moderators', I'm sure there are plenty of decent recaps out there that will get you up to speed.