If you are looking for something very bare bones, this is it - but be prepared to do some work. The two big work items here are that you have to create all of the thumbnails yourself and that you have to type in the path and filename of each image and each thumbnail. There are no size parameters in the plugin so resizing the display area will need CSS expertise(I'm guessing here - I didn't feel like investing the time to play around with it).

I had no problem installing and configuring this plugin in Joomla 1.5. I chose not to use it because I wanted to be able to link right into the gallery view from a menu item rather than have to first open a content item and then click on a link.