Just seen this thread so rather than read through the other answers so I'll offer the first name that bounced into my head: Tony Mandarich. Proclaimed he was the greatest lineman ever, boasted about his tattoo's and love of Guns N' Roses whilst offering to instead of play pro ball, go and fight Mike Tyson. So much hype, so many steroids, so little production.
vick was successful, but hyped alot...it was legit hype though williams wasnt hyped that much, he was a shocking pick more than anything.....reggie bush runs away with all the hype that year