Ellen DeGeneres and Portia Di Rossi, 15 Years
The talk show host and actress have been married since 2008 when California legalized same-sex marriage. They met in 2004, and despite the 15 year age gap, they moved in together the following year. DeGeneres said of Di Rossi, "It's the first time that I've known in every cell of my being that I'm with somebody for the rest of my life."