Who would win? In an all out war? And each of the Z fighters are at their best by the end of the Majin Buu saga. That means, Goten and Trunks can fuse into Gotenks and become SSJ3. Also Goku and Vegeta are allowed to fuse with the potara earrings to become Vegeto and do the fusion dance to become Gogeta. Also Gohan is Mystic, and Dende is also there on the battlefield to heal if necessary.
Oh, and Piccolo, Tien, Krillin, and Yamcha are also there to help out. Even though they are a lot weaker then the Saiyans
"There is good in this world, Mr.Frodo.....and it's all worth fighting for." Samwise Gamgee in Lord of the Rings: The Two Towers