I have seasons 1-10 on DVD and have watched them all, I have six books about Friends, I have one of the soundtracks of Friends, and I made a website dedicated to the show. (friendsfreak0.tripod.com) I can answer almost any question about episode numbers/names, lines/quotes, plots, character relationships, character history, etc. I can answer almost anything about things that happened within the show itself. I also have a little knowledge about costumes and set pieces.
I have watched all of the episodes in seasons 1-10 and have watched some of them twice or more. I have conducted personal searches for single lines. I cannot remember a time when one of these searches was in vain. I have downloaded an FAQ which answers several general questions about the plots and characters of the show and several questions about the making of the show. Best of all, I have my own site dedicated to the show!