You've most certainly come to the right place! There are a lot of great guilds here on POF.
Guilds and Clans contains various guilds of all types: Small, big, active, quiet, new, old. There is great variety here.
Then we have the guilds that have subforums on POF. There are three of them, each a great guild. These are the guilds that truly stand out against the others, due to their achievement of a subforum. Just take note; however, that there are many equally great guilds in the Guilds and Clans section. If you want to join a subforum guild, the best thing to do is to PM the Clan Leader of the group or post on their Recruitment Thread.
Black Bart's Krewe, lead by Charlotte Firemenace.
Partners N Crime, lead by Captain Del.
Shadow Sorcerors, my own guild. I'd be happy to answer questions if you're interested in joining the Sorcerors.
Best of luck finding yourself a great guild!