***UPDATE****
I have made 2 catagories, one is EVERY PLAYABLE SMASH CHARACTER EVER, and the other one is ASSIST TROPHY's. In the end you will find the most smartest character in the game and the dumbest.
The 10 Top Smartest
1. Mewtwo (He was a pokemon cloned to be the strongest ever, but he gained FULL knowledge as well, and even though at first he did not know his knowledge. You can tell now that he does.) Not in Brawl. If he was, I suppose he would be.... But they never say how smart he really is in-game.
2. Snake (Imagine a smart human in *This Present Day Time* he may not have a spaceship but his IQ is high, and he overplans enimies.) 'He may not have a spaceship,' wtf? How does-- Ugh, never mind. Anyways, yeah, he's #1 in Brawl, 2 if you count M2.
3. Olimar (WTF? Well unlike these other Hero's, Olimar takes studies and works a high job in his life, he even BUILDS back his own spaceship after a crash landing.) Actually, his ship rebuilds itself. And his job is basically an intergallactic truck driver. He may be smart, but not in the top 5.
4. Samus (Yep shes one of those girls that go around doing what she wants, and with 1,00o posts under this about her read their.) When has Samus ever demonstrated any cunning? Most of her problem solving involves blowing the brains out of aliens. Oh, and KNOWING HOW TO DRIVE A SPACESHIP DOESN'T MEAN SOMEONE IS REALLY SMART! ANYONE CAN LEARN HOW TO! Probably, seeing as how there are no real space ships (well, of Brawler's technology).
5. Mario (Mario is the same person, so no Dr. Mario is different and well he has done so much that he is smart. If doing alot of stuff makes one smart, Game & Watch is a freakin' Einstein. I don't see how Mario is that smart, really...
6. Starfox people (all of them are here for the same reason) I really don't know enough about Star Fox to judge them.
7. Meta-Knight (He DID NOT build his ship on his own, if you played super star youll see all of his comrads, but he Desined it.) He seems to be smart.
8. Wario (apperently he builds Einstein equipment within seconds, than acts like a ******. He is Very smart, but -85 percent wise.) NO. Please tell me this is a joke. What has Wario made, may I ask?
9. Ness (Defeated a the greatest evil with his mind, "something that was based off a horror **** scene) Paula beat Giygas, not Ness...
10. Kind Dedede (Build his hammer and stuff) DeDeDe is a screaming moron, just play any Kirby game.
The top 5 Stupidest
1. G&W (Simlple Sprite) He still is skilled in many things, so...
2. R.O.B (Artificul Intelligence) Robots are smart.
3. Jiggly Puff (No, Just No) Why? Well, I guess this fits.
4. Peach (kidnapped by the same person THOUSANDS OF TIMES) Peach is a total flake.
5. Yoshi (A SMART DiNO) Yoshi? The dumbest? Please. What about Ivysaur a plant-dino? Or the Ice Climbers, who obviously are based on down-syndrome kids?