Which music score is better? Original Japanese or American?
Both have good songs, but overall, I gotta go with the original Japanese, by the one and only Shunsuke Kikuchi.
One thing I find interesting about Kikuchi (and I didn't know this until now) is that when he scored the music for DBZ, he would compose a new package of music for the films, and then later incorporate it into the regular show (very rarely did his newer music packages debut in said regular show). His music score for DBZ movies 1 to 13 were respectively incorporated into the show in episodes #021, #047, #066, #097, #114, #141, #161, #191, #200, #234, #246, #273, and #289.