Hey Jim,
Off the top of my head, if I were looking for a link list script right now I would probably look for features like...
A very flexible template system that would be able to produce good SE friendly pages.
An advanced blacklist feature for blocking cheaters and maybe a whitelist as well.
Some kind of email confirmation and rejection template system.
A good site review system that would allow me to skip sites and come back to them later.
Maybe and email database for contacting submitters.
Those are all I can think of at the moment...
Regards,
SF