Zack's journey: Cocky > Hero > Dead *Makes out with Aerith's spirit* (Bastard)

Cloud's journey: Weakling > Shinra Grunt > Mental Test Experiment > Cocky/arrogant > Terrorist > Confused > Mental Headcase > High Powered Ex Shinra Grunt > Hero > Sick* > Doubtful* > Hero*

*Advent Children

I'm sorry Hypo, any way you look at it Cloud definitely had more character development then Zack.