Vinnie Delpino is Doogie Howser's best friend. He has stood by Doogie no matter what. When he and Doogie were 6 years old Doogie turned to Vinnie and said 'Hey, Vinnie, I wanna be a doctor.', Vinnie didn't laugh and stood by him.
When Doogie had his Dad's car towed and he hadn't the money to pay for it, Vinnie paid the $147 even though Doogie failed to take him to the coolest party.