What are the best practices for installing into the GAC on target machine?

My program uses some 3rd party UI libraries. They all install into the GAC on my development machine. Should I do the same on the target machine, or would I be better off just putting them into the application folder?

If I do install into the GAC, what options should I check on the file details dialog. Obviously the checkbox ".NET assembly", but I mean what about uninstall? Register as shared file? Replacement options?