I use Mingle Forum on all 16 of my Blogs. It's the easiest forum to install, and setup. Although it could do with a few new features as it's a bit behind the likes of vBulletin, and I'd like to see a better YouTube embedded links. Hopefully the developers will see these recommendations and make a few changes very soon. Thanks, Tech News365.
Oh, and hyperlinks show the full URL link, can you make them so they only show some text, with the link embedded.
I'd recommend installing a few additional wp-plugins for security too. I use the following:
1. Bad Behavious
3. Secure WordPress