D.C. is unironically the most LGBT-friendly place in the entire world.
San Francisco?
Perhaps. D.C. is unquestionably the most LGBT-friendly first-level subdivision (State/province, etc) though.
Hard for a place to be the most pro-LGBT in the world when there's no universal healthcare system to support medical transition or welfare state to support people disowned by their families.
In terms of attitudes maybe but in terms of the experience of LGBT people you probably have to go to the Nordics or Canada.
That's kinda the point, no? Iran provides free gender transition surgeries and America doesn't, yet one is undoubtedly better for LGBT people.