Darry- gym; he likes to show off his muscles and skills. Especially when they did football.

Dally- never liked school, never will.

Steve- auto-mechanics; enough said.

Soda- science; while he may not have been good at it he loved science, specifically biology, because he got to learn about animals.

Two-bit- lunch; he likes food.

Johnny- auto-mechanics; it's the only class he has that's only greasers so there's no worry about getting hurt by or compared to Socs.

Pony- English; he likes writing and reading so naturally he likes English.

Lily- Math; it's the only subject she's truly good at and is better than Pony at. Pony definitely got the smart end of the gene pool for the twins.