Highly Recommended Image Galley Plugin: WP Photo Album Plus
 

I wanted a simple easy setup image gallery plugin and spent a full day looking for such a creature.
I looked at the (not so) good, the ugly and the bl***y awful until I found WP Photo Album Plus:- http://wppa.opajaap.nl/
I highly recommend this plugin for ease of use with a multitude of settings.
I am using WP 3.1.3 ATA 3.6.7