Duon

Note: I know the this guy doesn't appear in any sonic game, but I though you should know the bosses from Super Smash Bros. Brawl since Sonic is appearing as a playable character. I don't have very much info on this boss, so I'll put in what I can and put more in later. You can battle this boss as anyone in Boss Mode of the game (You must unlock it first though)
1P's Character: Lucario, Snake, Sheik, Peach, Fox, or Falco (you choose three[four if no 2P])
2P's Character: Lucario, Snake, Sheik, Peach, Fox, or Falco (can be any of the other characters 1P didn't choose)

Crazy Hand

Note: I know the this guy doesn't appear in any sonic game, but I though you should know the bosses from Super Smash Bros. Brawl since Sonic is appearing as a playable character. I don't have very much info on this boss, so I'll put in what I can and put more in later. You can battle this boss as anyone in Boss Mode of the game (You must unlock it first though)
1P's Character: Any (you choose before starting Classic Mode[Hard or higher] or Boss Mode)
2P's Character: Any (you choose before starting Boss Mode)

Galleom

Note: I know the this guy doesn't appear in any sonic game, but I though you should know the bosses from Super Smash Bros. Brawl since Sonic is appearing as a playable character. I don't have very much info on this boss, so I'll put in what I can and put more in later. You can battle this boss as anyone in Boss Mode of the game (You must unlock it first though)
1P's Character: Ike, Marth, or Meta Knight for the 1st fight(you choose two[three if no 2P]). Lucas or Pokemon Trainer for 2nd fight(you choose[you'll play as both if no 2P]).
2P's Character: Ike, Marth, or Meta Knight for the 1st fight(can be any one of the other characters 1P didn't choose). Lucas or Pokemon Trainer for 2nd fight(you choose one).

Taboo (Tabuu)

Note: I know the this guy doesn't appear in any sonic game, but I though you should know the bosses from Super Smash Bros. Brawl since Sonic is appearing as a playable character. I don't have very much info on this boss, so I'll put in what I can and put more in later. You can battle this boss as anyone in Boss Mode of the game (You must unlock it first though)
1P's Character: All (you choose five[six if no 2P])(You must of picked up their trophies in order for you to choose them)(Wolf, Toon Link, & Jigglypuff can only be chosen for this fight when you beat the game once and defeated them in the hidden doors on The Forest area, The Ruins area, and the Swamp area)
2P's Character: All (can be any of the other characters 1P didn't choose)(You must of picked up their trophies in order for you to choose them)(Wolf, Toon Link, & Jigglypuff can only be chosen for this fight when you beat the game once and defeated them in the hidden doors on The Forest area, The Ruins area, and the Swamp area)

Master Hand

Note: I know the this guy doesn't appear in any sonic game, but I though you should know the bosses from Super Smash Bros. Brawl since Sonic is appearing as a playable character. I don't have very much info on this boss, so I'll put in what I can and put more in later. You can battle this boss as anyone in Boss Mode of the game (You must unlock it first though)
1P's Character: Any (you choose before starting Classic Mode or Boss Mode)
2P's Character: Any (you choose before starting Boss Mode)

Pokey Minch

Note: I know the this guy doesn't appear in any sonic game, but I though you should know the bosses from Super Smash Bros. Brawl since Sonic is appearing as a playable character. I don't have very much info on this boss, so I'll put in what I can and put more in later. You can battle this boss as anyone in Boss Mode of the game (You must unlock it first though)
1P's Character: Ness or Lucas (you choose[you'll play as both if no 2P])
2P's Character: Lucas or Ness (the opposite of the character you've chosen)

Meta Ridley

Note: I know the this guy doesn't appear in any sonic game, but I though you should know the bosses from Super Smash Bros. Brawl since Sonic is appearing as a playable character. I don't have very much info on this boss, so I'll put in what I can and put more in later. You can battle this boss as anyone in Boss Mode of the game (You must unlock it first though)
1P's Character: Donkey Kong, Diddy Kong, Captain Falcon, Pikachu, Samus, Pikmin & Olimar, or R.O.B (you choose three[four if no 2P])
2P's Character: Donkey Kong, Diddy Kong, Captain Falcon, Pikachu, Samus, Pikmin & Olimar, or R.O.B (can be any of the other characters 1P didn't choose)

Ridley

Note: I know the this guy doesn't appear in any sonic game, but I though you should know the bosses from Super Smash Bros. Brawl since Sonic is appearing as a playable character. I don't have very much info on this boss, so I'll put in what I can and put more in later. You can battle this boss as anyone in Boss Mode of the game (You must unlock it first though)
1P's Character: Pikachu or Samus (you choose[you'll play as both if no 2P])
2P's Character: Samus or Pikachu (the opposite of the character you've chosen)
Video of Battle: Click Here to see. (Note: I found this video, but I did not make it.)

Rayquaza

Note: I know the this guy doesn't appear in any sonic game, but I though you should know the bosses from Super Smash Bros. Brawl since Sonic is appearing as a playable character. I don't have very much info on this boss, so I'll put in what I can and put more in later. You can battle this boss as anyone in Boss Mode of the game (You must unlock it first though)
1P's Character: Fox or Diddy Kong (you choose[you'll play as both if no 2P])
2P's Character: Diddy Kong or Fox (the opposite of the character you've chosen)
Video of Battle: Click Here to see. (Note: I found this video, but I did not make it.)

Petey Piranha

Note: I know the this guy doesn't appear in any sonic game, but I though you should know the bosses from Super Smash Bros. Brawl since Sonic is appearing as a playable character. I don't have very much info on this boss, so I'll put in what I can and put more in later. You can battle this boss as anyone in Boss Mode of the game (You must unlock it first though)
1P Character: Kirby
2P Character: Kirby (Warning!: If 2P enters in this battle, you'll only have two live including the zero life)

Egg Bot

Your Character: Sonic, Tails, Knuckles, Cream, or Amy

Egg Frog

Your Character: Sonic, Tails, Knuckles, Cream, or Amy
Area: Egg Utopia

Egg-Go-Round

Your Character: Sonic, Tails, Knuckles, Cream, or Amy
Area: Techno Base

Egg Saucer

Your Character: Sonic, Tails, Knuckles, Cream, or Amy
Area: Sky Canyon

Aero Egg

Your Character: Sonic, Tails, Knuckles, Cream, or Amy
Area: Ice Paradise

Egg Totem

Your Character: Sonic, Tails, Knuckles, Cream, or Amy
Area: Music Plant

Egg Bomber Tank

Your Character: Sonic, Tails, Knuckles, Cream, or Amy.
Area: Hot Crater

Egghammer Tank II

Your Character: Sonic, Tails, Knuckles, Cream, or Amy
Area: Leaf Forest

Egg X

Your Character: Sonic, Tails, Knuckles, or Amy
Area: X-Zone

Egg Snake

Your Character: Sonic, Tails, Knuckles, or Amy
Area: Egg Rocket Zone

Mecha Knuckles

Your Character: Sonic, Tails, Knuckles, or Amy
Area: Angel Island Zone

Egg Spider

Your Character: Sonic, Tails, Knuckles, or Amy
Area: Ice Mountain Zone

Egg Ball

Your Character: Sonic, Tails, Knuckles, or Amy
Area: Casino Paradise Zone

Egg Press

Your Character: Sonic, Tails, Knuckles, or Amy
Area: Secret Base Zone

Egg Hammer Tank

Your Character: Sonic, Tails, Knuckles, or Amy
Area: Neo Green Hill Zone

Killer Turkey Gou

Your Character: Sonic or Tails
Area: Electric Egg Zone

Kamado MAX

Your Character: Sonic or Tails
Area: Mecha Green Hill Zone

Hopping Egg Vulcan

Your Character: Sonic or Tails
Area: Sleeping Egg Zone

Dangerous Ball Tower

Your Character: Sonic or Tails
Area: Gigalopolis Zone

Great Bane Motora Gold

Your Character: Sonic or Tails
Area: Turquoise Hill Zone

Dr. Eggman

Your Character: Sonic, Bean, Fang, Tails, Espio, Bark, Amy, Knuckles. or Super Sonic
Arena: Death Egg's Hangar

Metal Sonic

Your Character: Sonic, Bean, Fang, Tails, Espio, Bark, Amy, Knuckles. or Super Sonic
Arena: Death Egg's Eye

Black Doom(Middle Hero story, Hero boss)

Your Character: Shadow
Area: Space Colony Ark
Partner: Vector

Black Doom (Hero story and boss)

Your Character: Shadow
Area: Black Comet
Partner: Sonic

Black Doom (Evil story, Hero boss)

Your Character: Shadow
Area: Gun Fortress
Partner: Rouge

Metal Overlord

Your Team: Super Team Sonic
Starting Total of Rings: 50

Metal Madness

Your Team: Team Rose, Team Chaotix, and Team Dark

Robot Storm

Your Team: All

Robot Carnival

Your Team: All

Egg Hawk

Your Team: All

Egg Emperor

Your Team: All

Egg Albatross

Your Team: All

Black Bull2

Your Character: Shadow
Area: Death Ruins
Partner: Rouge

Black Bull1

Your Character: Shadow
Area: Lethal Highway
Partner: Sonic

Blue Hawk

Your Character: Shadow
Area: The Ark
Partner: Doom's Eye

Team Sonic2 [Team Dark story]

Your Team: Team Dark

Team Sonic1 [Team Rose story]

Your Team: Team Rose

Team Rose2 [Team Chaotix story]

Your Team: Team Chaotix

Team Rose1 [Team Sonic story]

Your Team: Team Sonic

Team Dark2 [Team Sonic story]

Your Team: Team Sonic