ralph.m, I hope I can help in trying to explain further what I hope to find in the perfect gallery software
I definitely know that I want the gallery to have a thumbnail pop-up when you hover over a picture that you click on to view the bigger version of said picture.
My apologies if it's not easy to describe the look of what I'd want to see in a gallery page), especially as I thought that Galleria could do the job that I required for said gallery on my site and even though it's a good piece of software, it could be better in various areas, especially where navigation and picture viewing is concerned. (Ironically enough, I just started a degree in Computer Studies in Liverpool and one of the modules involves website design, so I guess I'll be studying a bit about website navigation at a later date)
Navigation wise, with Galleria, you can view the gallery page in grid form (if that's any help), a slideshow, popout (but you can't save the actual picture using that option) and fullscreen.
I'd say that if you view the grid form of one of the gallery pages, that would be a good example of what I'm trying to explain when it comes to what I want the grid layout to look like within a frame on a page.
I've checked out Coppermine as well as Gallery and they're good software, but at the same time, I'm concerned about the fact that people might not like having to go through one or more folders just to view a picture, especially if there's only a small number of pictures in one gallery, for example.
In the meantime, I want to thank you and the others for the help that you've given me so far.