Interesting Character versus A Mary Sue

How to spot the difference

Basically, my way of telling the difference between a Mary Sue/Gary Stu from a character that will become a well rounded and interesting character. Let's start with the interesting character:

Interesting Character:

Name: Joe Blogs

Age: 17

Hair: Brown

Eyes: Blue

Mother: Elizabeth

Father: John

Hobbies: Playing video games, listening to music, hanging out with friends

Sports: Plays on the lacrosse team

Clubs/Team: Lacrosse

G.P.A: B

Secret Power: What?

Friends: Jason, Billy, Lizza

Weaknesses: Overly protective of friends and a bit too competitive on the field

Bad Habit(s): Smokes

Other info: Struggles with school. Trying to make things work with girlfriend and navigate High School.

Result: The basic outline of a believable character that can be easily fleshed out in any story with normal problems.

A Mary Sue character Amazing

Name: Alexander Martin Anthony Zack Ingrid Nathan Glenna

Age: 17, but so mature he looks older

Hair: Burnished Summer Gold with streaks of sunset orange

Eyes: Emerald Green with flecks of gold to match his hair

Mother: Queen Maria

Father: Prince Henrich

Hobbies: Creating music, writing, drawing, learning and speaking foreign languages, running, cycling, flying his plane, skiing, exploring exotic ruins, navigating his power boat, practising for his twelfth black belt in every known martial art, driving his racing car, scuba diving, vacationing in his numerous holiday homes abroad, looking after sick animals, taking care of the poor

Sports: Soccer, basketball, lacrosse, tennis, swimming, archery, horseback riding, gymnastics, badminton and bike racing

Clubs/Team: Math team, Drama Club, Art Club, Computer Club, Poetry Club, Multicultural Club

G.P.A: A +, of course

Secret Power: Read Minds, teleport, can fly without the aid of mechanical propulsion

Friends: Everyone in school, and many more besides

Weaknesses: Um, what?

Bad Habit(s): None, of course

Other info: Is the most amazing person EVER. Incapable of making enemies, except for his Arch-Nemesis, who is his Arch-Nemesis for some vague, almost unknown reason except that they are.

Result: Mary-Sue (or in this case, a Gary-Stu)

(N.B. The "secret" powers of the Mary Sue character does not necessarily mean they are a Mary Sue, IF they fit in with the characteristics of a given universe, such as, oh, let's say, the Percy Jackson Universe)