I've used Firefox since umm... 2004, I think? That sounds about right. I've loved it the whole time I've used it, and I'm actually using it right now. I even have a cute little fox as my theme. *squees of delight*
EDIT: I am a little aggravated with 18.104.22.168, simply because on my laptop it doesn't like to run addons or themes, and I'm not sure why. I just file it under Things That Make You Go GRR!