I have four.
1) Robin
2) Lucario
3) Young Link
4) Dark Pit
But overall my MAIN is Robin because of his moveset best suiting my playstyle and because I loved Awakening.
V I L L A G E R
AKA 'Killager'
It's just funny to attack people while keeping that dead-inside smile, or for Villager to have a giant realistic weapon.
I've been playing as the Mii sword fighter a lot lately. Not only do you get to play as yourself but you can customize the moves to your playstyle, which is nice.
Otherwise, it's been Fox since the original.
Before the game came out: Young Link
After the game came out: Young Link
Really only wanted to main him because I love the character, and luckily I love how he plays as well.