Not that famous, but Fred and his twin brother George are the major pranksters of the Weasley family in J.K. Rowling's famous series "Harry Potter." They adore playing jokes and breaking rules, and of course they were born on (when else?!) April Fool's Day.
Fred Mertz, played by William Frawley, was Ricky and Lucy's landlord and best friend in the TV show _I Love Lucy_. His whole name was Fredrick Hobart Edie Mertz.
Fred Burke was a major character in the later seasons of Angel. She was played by Amy Acker. In this case, 'Fred' was short for 'Winifred'. I thought it was cute, way better than the nickname Winnie.
If someone asked me the first person I think of when I hear the name Fred, I would automatically say Fred Jones from Scooby Doo - which isn't necessarily a bad thing! In the tv show, Fred was always good looking and a leader. On the other hand, another Fred kids will think of is Fred Figglehorn, the Youtube character, who is insane.
This name strikes me instantly as masculine with a good athletic and academic mix. It is traditional and I think of an All-American type man or boy, a college baseball or football player.