It's interesting that literally everyone from TGWTG I follow I discovered independently from the site.
I discovered Brad after a friend linked me his Crystal Pepsi reviews. Obviously I still follow him.
I discovered Spoony when I was working on the 'Phantasmagoria 2' Wikipedia article (NEEEEERRRD!!!) around the time his LP went up and fans were linking it in the article. I still follow him, though only his reviews.
I discovered Paw through his King's Quest retrospective on YouTube. I rarely follow him unless he posts old school gaming stuff.
I knew about PushingUpRoses because of her 'Callahan's Crosstime Saloon' LP, but didn't get into her work until I discovered her LP Shorties through Paw. After she quit the LPs, I've followed her on and off as I've yet to get into her newest on-camera reviews.
Nostalgia Critic I discovered while Googling "Titanic: The Animated Musical". It wasn't until 'Kickassia' when I checked out everyone else on the site, but nobody stuck with me for very long.