how about http://www.photopost.com I am using it on my Africa travel image gallery site here http://photos.africapoint.net
Go for coppermine. My site says why... http://shichibukai.org 6 months old google PR4 6,000+ google indexed pages 400 google back links
Coopermine for features and SEF its great, but still have a lot of security bugs ScriptBiz is better. I run one website with this gallery and i have no problem
coppermine is easy to set up, easy to use and easy to get your server hacked when it is installed! If you do not update it as soon as a new release comes out your site will probably be the target. Go for gallery2 - it has not let me down yet.
True true..i was using coppermine but it got hacked by a spammer who used it to send spam and my host closed my account