(I ended up not going on the computer at all yesterday; I'll make up the missed day on one of my free days.)
The first fanvids I ever watched were on a VHS tape that a friend of my sister's brought over to our house in the summer (or maybe early autumn) of my freshman year of high school. I'm fairly sure it was a vid show from Otakon 1997, or maybe a premiers vid from the previous Katsucon, because the only vids I remember (probably because they were the only ones I recognized both the canon and the song) were this Ranma 1/2 vid to the Proclaimers' "I'm Gonna Be (500 Miles)" and this Dragonball vid to TMBG's "Particle Man". We watched them on the VCR in the downstairs sitting room, the one where the remote control wasn't wireless.
In a way that was also my intro to real life organized fandom - I wouldn't have enough internet access to be involved in online fandom for several more years, and before that I'd been limited to things like pro-published accounts of the history of Star Trek fandom. But now I had met someone who had been to actual cons! Watched actual fanvids! (He still has all his old tapes, we re-watched them a few years back, I could probably track down the exact one if I needed to.)
My taste in fanvids has not noticeably improved since then. (My current strong desire is for someone to vid the Venom movie to "I came in like a wrecking ball")
On that note, all the people wanting a home for vidders: AMV.org (ETA: actually http://www.animemusicvideos.org )has been going for nearly 20 years, has been the undisputed hub of AMV fandom nearly that whole time, and it took me literally five minutes to track down copies of vids I hadn't seen in 20 years. Why aren't more people talking about AMV.org? (...probably because it doesn't stream, embed, or allow comments. It does a very good job of making vids findable, though!)