S Tier (Super Tier) From the heavens.
Meta Knight 10.0
Snake 9.9
A Tier (Top Tier) On top of the mountain.
Wario 9.7
Diddy Kong 9.6
Falco 9.6
King Dedede 9.5
Marth 9.4
Pikachu 9.3
Mr. Game & Watch 9.3
B Tier ( Very High Tier) Almost at the top of the mountain.
Olimar 8.9
Ice Climbers 8.7
Zero Suit Samus 8.5
ROB 8.2
Lucario 8.0
C Tier (High Tier) Higher than the middle part of the mountain.
Kirby 7.9
Toon Link 7.8
Pit 7.6
Donkey Kong 7.4
Luigi 7.4
Fox 7.3
Wolf 7.2
Peach 7.1
Zelda/Shiek (Used as both) 7.0
D Tier (Middle Tier) Half way there.
Squirtle (no forced switching, no fatigue) 6.8
Ness 6.7
Lucas 6.6
Zelda 6.5
Shiek 6.3
F Tier (Low Tier) At the low part of the mountain.
Sonic 5.9
Bowser 5.8
Ike 5.7
Pokemon Trainer/Charizard (as an average) 5.6
Yoshi 5.4
Mario 5.2
Samus 5.2
Ivysaur (no forced switching, no fatigue) 5.0
G Tier (Bottom Tier) On ground level.
Jigglypuff 4.9
Captain Falcon 4.8
Link 4.6
Ganondorf 4.4
Popo 4.0
Nana 4.0
F Tier (Worthless tier) Underground.
Solo Olimar 1.0
This list was thought of from the following evidence : live tournament results, online ladder rankings, characters performance on starter stages, and overall good match ups against the rest of the cast.
I'll continually keep updating this.
Compared to the new tier list 3.0
Condensed Version
S: Meta Knight, Snake, Wario, Falco, Diddy Kong, King Dedede
A: Marth, Mr. Game & Watch, Pikachu, Olimar, Ice Climbers, R.O.B., Kirby
B: Lucario, Zero Suit Samus, Toon Link, Pit, Donkey Kong
C: Peach, Luigi, Fox, Wolf, Sonic, Sheik
D: Bowser, Zelda, Pokémon Trainer, Ike
E: Lucas, Mario, Ness, Yoshi, Samus
F: Jigglypuff, Captain Falcon, Link, Ganondorf