zapdos question

You do more over-damage with one bar and you can almost every time throw a half a charge bar before fainting

I think thunderbolt. Better for dodging too.

Thunderbolt is better, but not by that much. Zap Cannon is still a fine move.

Cycle DPS is higher for Thunderbolt (20.76) than Zap Cannon (20.63). Small difference. Both are better than Thunder (18.53). Two bar makes it a bit easier to use, and Thunderbolt hits quicker, which will be good in PvP, when it eventually hits.