Vbulletin, she IS a rocking!
 

I have not been on vbulletin-based forums too much lately. But, I must say that this justifiably "non-free" but inexpensive little script is kicking ASS. I would say that there are a lot CMSes out there, Drupal has turned me into a mystic on the subject of Taxonomy. But, for straight, up, rapid-fire to and from between brothers in the night, vb is king. Impressed!

well you just missed the forum fiascos as of late...

it is running pristine right now though :pimp

have you tried SMF? IMO its much better than VBulletin.