Good user ban plugin?

Hey everyone!

I was wondering if anyone could recommend a plugin that would enable me to ban users permanently from a site?

I want to be able to ban a user if say they break the rules of the site, or are troublesome. Did a search but anything good hasn't been updated in awhile. :slight_frown:

Thanks for any recommendations in advance!
Nathan P.

PS. I wouldn't mind seeing this being used as an idea for a plugin here... :wink: