how about checking
Mkportal and see if it has the features you want. this one is also FREE.
one live example of a site using this script is
CPFools
i also like this portal and i'm currently testing it
at My Test Site.
i won't say this is the best. it would depend on what kind of features you want. this one's i found to have a complete feature. gallery, shoutbox, blog system, toplist, chat and many more. it won't hurt checking this out.
regards,
afterglow