My all time favorite was Vegeta, he is like me when it comes to being arrogant and tough and heartless at first, then when you see him for what he truly is, he is a good guy. I cried when he was killed by Frieza, that was the first time I cried to an anime (the second and most recent was Elfin Lied, but that's another story). Vegeta would try so hard to be the best, but couldn't, and I can relate to that.
Both Trunks were cool, the sword onwed, and I am glad he kill that basterd Frieza. I hated Frieza for killing Vegeta, plus that is Bulma's and Vegeta's kid, what's not to love.
Goku is ok, he is nice, and I like his hero personality, but I hate that he is always a step above Vegeta. But all in all a good character.
Gohan and Goten are cool, not much about them.
Picollo is awesome, I liked how (like Vegeta) he was evil than slowly became good. Plus he was the only non-sayian who still was very strong.
krillin is definately funny, I like the Distructo Disk. And yes he is the strongest of the humans.
Yamcha is my favorite human, cause he looks very cool, plus he had long hair, then during the Garlic Jr. OVA it was medium, and after it was short and spiked. I wish he would have played a bigger role in DBZ like he did in DB.
Tien is cool, so is Choutzou, even though Choutzou had the smallest role.
Bulma is my favorite female, mainly cause she is Vegeta's wife.
I hate Videl.
I really hate Frieza.
Cell was ok for a villian.
Majin/Fat Buu was the best cause he was fat (like me) but he wasn't ugly like the others.
Conclusion: God, how I miss that show.