These are the available charcaters(remember you can create your own too)
Saiyans:
Majin Vegeta,Bardock,Nappa,King Vegeta,Radditz,Veggeto,Turles,Brolly(you can make up a Saiyan)
Nameks:
Piccolo,dende,Nail(can make up a Namek)
Humans:
Master Roshi,Hercule(Mr.Satan),Krillin,Yamcha,Tien,Chi Chi(can make up a Human)
Half Race:
Gohan,Chibi Trunks,Marron,Bra,Pan,Gotenks,Older Goten(can make up a half race person)
Androids:
16,17,18,19,20(can make up an Android)
Bio Mech Androids:
Cell(Can make up a Bio Mech Android)
Other Evil Beings:
Majin Buu,Garlic Jr.,Freiza,King Cold,Captain Ginyu,Recoome,Jeice,Burter,Dodaria,Zarbon,Amondo,Bojack,Janemba,Rirudo Shogun
Other Good Beings
Fat Buu,Chiaotzu,Supreme Kai