I personally wouldn't say that Samurai Champloo is better than Dragonball Z. They are just different in their own ways. Dragonball Z has intense fighting scenes which deals with hand to hand combat and using powers while Samurai Champloo has the sword fights. There are funny scenes that can be found in both of the animes as well. Besides they both have their own plots and animation stlye. Samurai Champloo has a newer animation stlye but that doesn't make it better than Dragonball Z because many people consider Dragonball Z's animation to be good as well.
Dragonball Z is one of the great animes and loved by so many people so how can it be less deserving than Samurai Champloo.
Oh yeah, I also like to watch Samurai Champloo. I recommend anyone who hasn't watch it to do so.