Here's my top 10. The first two characters are already locked in as mains for sure. The rest will either end up being mains are will just be characters I play for funsies on the side.
1.

He's the most badass character in Smash and Kirby, he fits the style of play I have in every fighter I play, he's fast, strong, and stylish. He's ************* Meta Knight. 'Nuff said.
2.

Because it's Megaman. I mean, as soon as he was announced I almost broke my laptop in hype. From his sound effects to his moves, he's true to his 8 bit self. Megaman is all kinds of awesome, and he's been the only character I've been playing in the demo.
3.

She's hot, and she's fast and deadly. I mess around with her a little in Project M, but I'm really looking forward to trying her out in Smash 4. Very strong potential to be added to my list of mains.
4.

Cuz he's been my all time favorite starter pokemon since the RBY days. Hopefully he'll be viable.
5.

I love the Starfox series, grew up with it, and Fox and Falco are my all time favorite Starfox characters..which leads me to..
6.

Fox. He'll probably be an instamain no matter if he's good or bad.
7.

My second favorite Kalos starter, Delphox being my favorite. (Delphox for DLC pls.) He looks fast and strong, and I love his Maximum Spider style Final Smash.
8.

She's beautiful and cute, and her playstyle kinda reminds me of my Soul Caliber 5 main, Viola. Very strong possibility for my list of mains.
9.

I've always been interested in playing Sheik, but for some reason never picked her up. I'm definitely gonna try her out in this game though. Her playstyle looks sick.
10.

She's very pretty and really graceful. Don't know much about her or her playstyle, but she looks interesting.
Here's to hoping that Mewtwo, Krystal, and Delphox make it in as DLC >_<