#4 Gary Neville
Perhaps the most famous name on this list Gary Neville was part of the famous 'Class of 92' which also included his brother Phil, Ryan Giggs, David Beckham, Paul Scholes and Nicky Butt.
He made his debut for United at the age of 17 years 06 months and 29 days in the UEFA Cup against Torpedo Moscow. He spent his entire playing career at United making him a one club man. When he retired, he was United's second longest serving player at that time, behind Ryan Giggs.
Neville joined United just after school and led them to the FA Youth Cup title in his first season. He established himself as United's first choice right back in the 1994-95 season and remained so till his retirement.
All in all, he made a total of 605 appearances for the club and won a total of 20 trophies, including eight Premier League titles and two Champions League titles. Currently, he works as a pundit for Sky Sports.