Which shapechange forms are good for blasting?

[RoboEmperor]

At-willl fireballs as SU ability and stuff like that.

Storm elementals is one, but requires changing forms every round to get around that once per minute restriction on its blasting.

[MisterKaws]

Pyro/Cryohydras are as good as you get for really anything.

[Geddy2112]

I have always been partial to becoming a dragon-the breath blast is great, although it needs recharge. The thing is, you get an awesome set of attacks/abilities and the ability to cast all of your other blast spells in the meantime.

I won't lie and say that rule of cool does not factor in here...