Crash would be great (and ironic), but I would really like one of the Battletoads. ^^

Shadow, Eggman, Crash, Shantae, and Noah & Mio would be my top requested characters.

As for Goku? Eh. I can personally take or leave him.
I was one of the people that actually wanted King Mickey over Sora because, c'mon, the visual of Mickey Mouse (Disney) fighting Mario (Nintendo) would have been fucking AWESOME!!!

As far as the argument of the Dragon Ball fanbase jumping in and being insufferable if Goku were to join the roster...

Like the Smash Bros fanbase themselves aren't already insufferable? Not to mention the Sonic fanbase which are the ABSOLUTE WORST in gaming, in my view. And in all of fiction, there's only one fanbase I can think of that's more toxic, insufferable, and just God Awful than Sonic's. And that's Star Wars.
There's also Zelda fans and Pokemon fans who can be pretty bad in their own way.

We're in WAY too deep in that territory to turn back now.

You want insufferable? Try Star Wars fans. Several Star Wars actors across the franchise (Jake Young, Kelly Mae Tran, Ahmed Best and Moses Ingram) have been viciously harassed by Star Wars fans, ruining Jake Young's life and nearly driving Ahmed Best to kill himself. Calling the Star Wars fanbase toxic is putting it lightly. -_-

I don't see any characters originating from anything outside of video games ever coming to Smash Bros.

He won't - so don't worry.

Good

Guile, it's your turn

I personally would love to see Goku in the game - as a Dragon ball fan.

Anyone who doesn't think Smash is a fighting game is worse than a literal Nazi.