Each Smash game, I've originally main'd my current main of the previous game.
Seeing as how I main'd Toon Link in Brawl up until I stopped playing that game in 2009, I will main him again.
I did the same thing with Fox (my then and current Melee main) in Brawl and Kirby (my then Smash 64 main) in Melee.
I wonder who I will end up main'ing though.
I always am good with Ness, I always like Captain Falcon and Kirby, Lucas' style fits mine and I like him, I'm good with Pit in Project M, Toon Link is just the epitome of how I play (aggressive as a raging bull), Mario is my guy in Smash 64, and I love Fox in Melee.
So yeah, any of those characters, plus potentially Luigi, Marth, Roy, Mewtwo, Diddy Kong, Ike, Sonic, Mega Man, and heck, even the Villager could be my final mains of the current crop of past characters and confirmed newcomers.
My top 5 bets are:
5. Ness
4. Mario (I get the "unremarkable" vibes from him again)
3. Fox
2. Mega Man
1. Toon Link