Jamie Sadlowski is a two-time long drive world champion, probably the kind of competition you would've seen on Transworld Sport back in the day. He has a personal best drive, according to Wikipedia anyway, of a whopping 445 yards.
In this video he doesn't quite hit that distance, though that'll have something to do with him being on his knees while smacking a drive that goes a not inconsiderable 331 yards.
h/t Eye on Golf