When I first saw the title of the thread I assumed we were going to be discussing musicals that feel more like straight plays, like 1776 for example, which goes on for a very long time without a single note being sung. Instead we have a poorly worded thread about sexual identity stereotypes.
Bad wording aside, this is still a somewhat interesting topic to discuss. There are, after all, a number of people out there who instantly reject the idea of musical theatre based solely upon that stereotype, and there are musicals out there that may change their minds, and musicals that they may feel validate their point.
My answer to the question at hand is Book of Mormon. I think 1776 may be able to answer this question as well. Book of Mormon works because of the frat boy sense of humor that Comedy Central specializes in and gears specifically to the 18-30 year old male demographic. 1776 because of the sense of parasitism it can induces coupled with the lack of big dance numbers and jazz hands. There is nothing wrong with big dance numbers and jazz hands, but for those that view musical theatre as part of a gay stereotype, they see these things as perpetuating that stereotype. Just my two cents. While the wording of the question is kinda offensive (and yes, phillypinto, it really is), it is still worth discussing.