For me, the best Dragon Ball Z game is a Counter-Strike 1.6 mod called "Earth's Special Forces" (ESF). It's probably named that way because in the FUNimation dub of DBZ when Future Trunks tells Goku that all Z fighters have been killed by androids, he refers to them as "Earth's Special Forces". The mod has no storyline. You just fight bots on various maps in DBZ universe. What I love about it is that it really captures the destructive element of DBZ fights, even without destructible environments. The extensions of the mod like ECX RC2 allow you to spam ki blasts that create explosions as big as half of the map. It was really crazy and fun. Plus the abundance of transformations. You could play as freaking Gogeta SSJ4. So far no officially licensed DBZ game has topped that for me. DBZ games shouldn't be fighting games or action RPGs. They should be chaotic sandboxes with custom fusions, overpowered transformations, destructive environments, and planet-busting explosions. I hope that DBZ: Kakorot will feature at least a drop of that.