Lots of people are Al fans and lots of Al fans are people... uh, wait a minute... you know what I mean. I'm talking about mutual admiration. I can't say for sure that Al is a fan of "Friends" and Jennifer, Courtney, Lisa, David, Matt, and Matthew are fans of Al, but the evidence sure points that way.
Al sightings
In the last episode of season 1, where Rachel finally finds out Ross is in love with her, Ross's plane lands at gate 27-B.
In the same episode, Joey's girlfriend's name is Melanie.
In the episode where Monica wants a sperm donor, one of her choices is 27 years old.
In the same episode, Chandler wears a t-shirt with 27 on the sleeve.
During an episode in the last season, Monica's hair frizzes up due to the humidity, and Chandler comments that he's going home with "Weird Al" Yankovic.
Friends sightings
Al has done a concert only parody of "I'll Be There For You" which is the Friends theme song. His parody is called "The Theme To Home Improvement." The chorus line is "I'll repair for you."
Al and Suzanne's official wedding photo is a parody of Jennifer Anniston and Brad Pitt's official wedding photo.
Al's middle name is Matthew and two actors on the show "Friends" are named Matthew. Matthew Perry plays Chandler, and Matthew LeBlanc plays Joey. Of course Al's parents couldn't have forseen this, but it's still a cool coincidence.