I need a blaster...

[Darklone]

I'd go dragon shaman but not for blasting. He has a nice HD. Combine this with the wilder build shown a little bit higher and you'll have a nice blaster who can take a lot of hits.

 

[BlueBlackRed]

I've played in one gestalt game which I loved.

I played a conjurer/druid who specialized in summoning everything under the sun.

And if you're still wanting a blaster someone else in the game played a warmage/rogue and puting a lot of focus on the orb spells adding the warmage edge and sneak attack damage during the first round.

 

[Sejs]

Bard/barbarian. You blast with your axe, like in Guitar Hero 2!

Okay, I am so seeing the video for Thunderhorse running thru my mind right now.

 

[IanB]

Warlock/Rogue with a source of improved invisibility of your choice, should be a very nasty single target blaster.

If you want multi-target/area effects, psion/wizard lets you double up on int, put your utility in the wizard slots, and just go nuts with damage with the psion levels.