I am a Roman Catholic and sometimes go to the following service here in London:
http://www.sohomasses.com/
It's a service for LGBT folk, their families and friends. It is a mass organised by the Diocese of Westminster (effectively, the Catholic community serving central London). Unsurprisingly, it's not something that has been welcomed by sections of the Roman Catholic church but, for me and others who attend, it is very reaffirming.
The church attracts a wide variety of worshipers, including many non-LGBT folk and people of all ages and backgrounds.