In Dragon Ball Z before Vegeta sacrifices himself in the fight with Majin Buu, Vegeta asks Picolo if he is going to see Goku when he dies.
Picolo answers him that only great warriors who did great great deeds are able to keep their bodies, and that Vegeta had had a life of selfish and only though of himself. And so far so good, as in other ocasions, for example when Goku died for the first time, kami told Goku the same thing.
But looking at other characters (Raditz, Ginyu Special Forces, Frieza, Cell, Dabura, ...) they were able to keep their bodies after death, and we all know they were evil.
One would assume that if the characters above were given the body after dead, Vegeta should be able to keep his, right? And to add to that, Vegeta sacrificed himself trying to save the planet earth and his family.