I think the highest damage ones are probably the elemental circles. If you want, you could always grab one of the ones I don't get, so we can work together more efficiently. I'm still not sure between Detereorating Corrosion, Searing Flame, or Perfect Freeze.... Of the lot, Searing Flame can provide the most damage, for the whole team even, especially with its spellshape aura. There others are more situational, though Perfect Freeze will make enemies secretly hope they don't hit us a lot.
Detereorating Corrosion could prove useful in a dungeon setting, dealing double damage to objects, but it's still situational. Still, it's got good damage and has a lot of debuffing.
The only one I'm not considering is Shocking Current. I like electricity damage as an energy type, and it's got some fun abilities, but... You know what, I just talked myself back into considering it. >_<