I don't think that we should all try to tackle an entire tier-list at once. Ordering 30-something characters all at the same time is really tricky, so I tried to just make a high-tier list and concentrate on my choices.
MK
Snake
G&W
ROB
Falco
MK: Speed, priority, and a good recovery. He is unstoppable in the right hands.
Snake: Very strong, but his recovery is stopping him from getting the top spot. He also can get punished and chaingrabbed by the lighter chars. He might fall a few spots if everybody finds out how to abuse his weaknessess. But for now he remains a heavy, powerful character with cannot be ignored. Furthermore, he seems to counter MK.
G&W: A killing machine. He may be one of the lightest characters in the game, but it doesn't matter how heavy you are when your oponent is face down in the dirt. With disjointed hit-boxes, the nastiest turtle you've ever seen, edgeguarding bacon, and a projectile-absorbing bucket. This guy should be feared.
ROB: The classic camper. This guy has a 5-second recovery, a wicked aerial game, and 2 projectiles. When you add all of that together, you get is an edguarding demon who pwns you in the air and weighs as much as a hippo. However, this WALL-E has a tricky time killing people, so it stops him from reaching the top.
Falco: Lasers, speed, a reflector, and the meteor-smash everybody hates. Falco is a really nasty offensive beast who can punish people who aren't careful when the get back to the stage. His reflector can counter projectiles and hurt approaches while his laser lets him annoy at a distance. This bird has a nasty chink in his armour though, in the form of his recovery. To put it bluntly; it sucks.
Characters that might make it:
Diddy Kong
Pikachu
Dedede
Donkey Kong
Toon Link
Wario
