I tend to like characters who develop. Gohan changed alot over DBZ, from the sheltered momma's boy to a kick ass fighter, while growing up over the course of years.
Vegeta also changed quite a bit. From the down right evil bad guy to the anti-hero, back to bad guy and finally to hero. The bit in Final Atonement where he finally realizes that not only does he really care for people, but that he's arrogence has put them in danger and it's up to him to make that good no matter the cost is pretty cool. As is the scene where he finally hugs Trunks. As silly as DBZ could be at times, it could also come up with some great moments.