I have only 2 successful chao, dark and hero, both of which i raised to win all the races.
I've always believed that a fast chao is a winning chao, both are speed, but I've never really been a good chaos raiser. I just cram them with skeleton dogs, half fish, chao fruit, and chaos drives. Then i leave to earn more rings and collect more animals/drives. But I still get that sort of fatherly pride knowing they're both very strong for their age.
Conquering the world, one step at a time.