I've clicked on Photium as that's what I use
However, as to whether it's 'best' I have no idea, as I've never used clikpic, so can't make a comparison.
However, the things I like about Photium are:
-excellent customer service
-new features being added regularly
-some flexibility in the templates
-slideshow on the front page
-the ability for visitors to leave comments by photos
-800px wide images can now be displayed
Maybe clikpic can do these, don't know, never looked.