Isn’t Anakin the very definition of a Mary Sue? At least in TPM he is. He’s the best pilot in the world at age 5 for no reason other than that he’s supposed to be.
No, he isn’t a Mary Sue. First, not everyone loves him or is otherwise fascinated by him. Obi-Wan doesn’t seem to care much for him, and neither does Yoda or the rest of the Jedi council. All of them think it’s a bad idea to train him. He is also a slave, and his owner, Watto, thinks so little of him that he doesn’t mind putting his ownership of him up as stakes in a bet.
Second, he never intentionally used the force, which is how it should be, because he hadn’t had any force training yet. He used it unconsiously, to enhance skills that he had already learned in the conventional way, which is in line with Qui-Gon’s explanation to his mother. When we meet him, he has already podraced many times, and has failed many times. His other significant accomplishment of the movie, destroying the ship that controlled the droid army, was something he bumbled into in Jar Jar Binks fashion. Autopilot got him most of the way there in the first place, and then he started trying random things, which resulted in a stray shot hitting the reactor.
He was an annoying character, but he wasn’t a Mary Sue.