Ok I know everything about Vegeta's personality.
Vegeta has an ego and a superiority complex. Until he tangled with goku he was the strongest warrior he knew. Then goku comes along with his hair and his orange clothes and dethrones Vegeta in what he thought was best at.
This caused a rift in Vegeta's pysche. On one side he still thought he was the best, but on the other he realized that Goku was past him in strength speed and over all ability. This caused Vegeta to loathe Goku. He didn't care for anyone else in the Z-team. He eventually opened up for Trunks, but thats besides the point. Up until He accepts Goku's strength in the Buu Saga, he was very indifferent about everyone.
When he fought on the side of the Z-righters instead of the bad guy, it was only so that Goku would not be killed in hopes thats Vegeta could once again reclaim his throne, in his own mind at least.
When Vegeta was put under the control of that little wizard guy, his power increased so much he believed he could beat Goku. Then he battled Goku and beat him, or so he thought. Then.... with Goku gone, Vegeta became placid, he felt peace. He decided the right thing to do would be to make the ultimate sacrifice for Trunks to live. He killed himself.
When Goku finally told Vegeta that he wasn't at his full potential to defeat Vegeta in that fight, Vegeta realized that no matter how much power he consumed, no matter what level he trained too, Goku would always be there to surpass him.
For the rest of the series Vegeta is, I wouldn't say a broken man, much less of how he used to be. He's kinder to his wife and son. And he and Goku have sort of a relationship.
Damn thats a mouth full.
