I wrote this list ages ago, I also trimmed off some of the crazier stuff.
Zoë Wanamaker as Son Goku, Son Gohan, Son Goten, Bardock, Vegetto, Gotenks, and Gogeta.
Yes, I want a mature lady to play all of Nozawa's roles, it makes sense, though she's definitely not had much experience playing boys, I think she could do a perfect Boy voice if she wanted. She's an American-British Actor most known for her roles in My Family, Harry Potter and Doctor Who.
Tiffany Grant as Bulma, Bra
Her most memorable role was as Asuka in Evangelion, and I can definitely
hear her playing Bulma.
Colleen Clinkenbeard as Kuririn, Yajirobe
Mirroring her role as Monkey D. Luffy, also played by Mayumi Tanaka of course, she could definitely pull off these two
Billy West as Karin
Crispin Freeman as Piccolo
It would sound awesome...
Yuri Lowenthal as Yamucha
Tony Oliver as Tenshinhan
Johnny Yong Bosch as Vegeta
Spike Spencer as Trunks and Child Trunks
He could definitely pull both off...
Jessica Boone as Puehr and Chaozu
Puerh should sound cute, not irritating, and she could probably play Chaozu well too...
Celebrity/Guest Voices: THINGS GET WEIRD HERE!
Mark Hammil as Emperor Pilaf/Garlic Jr.
Tom Baker as Tao Pai Pai
Samuel L. Jackson as Adjutant Black
Christopher Ryan as Commander Red
Kelsey Grammar as Piccolo Daimao
David Hyde Pierce as Piano
Zachary Quinto as Raditz
Brian Blessed as Enma-daioh
John DiMaggio as Nappa
Frank Welker as the Saibai-men
Tim Curry as Freeza
Patrick Stewart as Cell
Frank Oz as Majin Buu
Bryan Cranston as Baby
Laurence Fishbourne as Yi Xing Long