What is the Best Forums Application for a Website that Works using MySQL PHP and Has Login, Spam Controls?

I had PHPBB on a website but the spam bots got in there and it was difficult to maintain and clean up. Is there a better way to install and manage a Forums App? Maybe with an advanced login page or something with a CAPTCHA? Any ideas. Please provide links, thanks. Also would like a Forum App than I can customize to look and feel of website or is skinless and can run within a DWCS3 template design (if that is possible?).