I have decided to compile a list of all voice actors in the American version of SSBB. Please note that the list is not quite complete, but very close. If you can add or correct me, please feel free.
Mario: Charles Martinet M*
Luigi: Charles Martinet M*
Peach: Samantha Kelly*
Bowser: Eric Newsome*
Link: Akira Sasanuma*
Zelda: Jun Mizusawa M*
Sheik: Jun Mizusawa M*
Ganondorf: Hironori Miyata*
Toon Link: Sachi Matsumoto*
Pikachu: Ikue Ootani M*
Pokemon Trainer: Sarah Natochenny OR Michelle Knotz
Squirtle: Billy Beach/Jimmy Zoppi
Ivysaur: Bill Rogers*
Charizard: Shin-ichiro Miki*
Jigglypuff: Rachael Lillis M*
Lucario: Sean Schemmel
Fox: Jim Walker*
Falco: Dex Manley*
Wolf: Jay Ward*
Samus: NA M*
Zero Suit Samus: Alesia Glidewell*
Donkey Kong: NA
Diddy Kong: probably NA
Sonic: Jason Griffith*
Snake: David Hayter*
Olimar: NA *
Mr. G&W: NA M*
Pit: Lani Minella*
Ice Climbers: Sanae Kobayashi M*
Ike: Jason Adkins*
Marth: Hikaru Midorikawa M*
Ness: Makiko Omoto M*
Lucas: Lani Minella*
Yoshi: Kazumi Totaka M*
Wario: Charles Martinet*
ROB: NA*
C. Falcon: Ryo Horikawa M*
Kirby: Makiko Omoto M*
Meta Knight: ???
King Dedede: Masahiro Sakurai*
The only one I am missing is Meta Knight, and unsure on the Pokemon save Jiggs and Pika.
Mario: Charles Martinet M*
Luigi: Charles Martinet M*
Peach: Samantha Kelly*
Bowser: Eric Newsome*
Link: Akira Sasanuma*
Zelda: Jun Mizusawa M*
Sheik: Jun Mizusawa M*
Ganondorf: Hironori Miyata*
Toon Link: Sachi Matsumoto*
Pikachu: Ikue Ootani M*
Pokemon Trainer: Sarah Natochenny OR Michelle Knotz
Squirtle: Billy Beach/Jimmy Zoppi
Ivysaur: Bill Rogers*
Charizard: Shin-ichiro Miki*
Jigglypuff: Rachael Lillis M*
Lucario: Sean Schemmel
Fox: Jim Walker*
Falco: Dex Manley*
Wolf: Jay Ward*
Samus: NA M*
Zero Suit Samus: Alesia Glidewell*
Donkey Kong: NA
Diddy Kong: probably NA
Sonic: Jason Griffith*
Snake: David Hayter*
Olimar: NA *
Mr. G&W: NA M*
Pit: Lani Minella*
Ice Climbers: Sanae Kobayashi M*
Ike: Jason Adkins*
Marth: Hikaru Midorikawa M*
Ness: Makiko Omoto M*
Lucas: Lani Minella*
Yoshi: Kazumi Totaka M*
Wario: Charles Martinet*
ROB: NA*
C. Falcon: Ryo Horikawa M*
Kirby: Makiko Omoto M*
Meta Knight: ???
King Dedede: Masahiro Sakurai*
The only one I am missing is Meta Knight, and unsure on the Pokemon save Jiggs and Pika.