So let's assume as of now that Sonic is going to return in the next Smash game. If he does, are you hoping for any new changes? This can range from his moveset to really anything that involves him and his franchise. Wish away.
My personal wishlist:
Moveset: Assuming none of it makes him too powerful, I want:
Better Homing Attack
Different Side or Down B (my best idea is only a skateboard that he can throw)
Tornado (w/ Tails) for recovery
More killing moves
A f-air that can be used multiple times similar to Meta Knight's
More small fan service such as making his d-tilt the sweep kick and d-air the stomp
Music:
What I'm Made Of
Crush 40's Seven Rings in Hand
Un-Gravitify
Knight of the Wind
With Me
Stage:
Similar to that in Project M but bigger. What Project M's is is just a flat surface with a swinging pendulum. I personally love simple/less-gimmicky stages, with maybe a few gimmicks.
As for trophy's/stickers I don't really have any notable preferences.