Vbulletin for paid and myBB for free. Both are really good with a lot of features. If you have time, you could get phpBB and fit it with all the mods available that you like but that takes time and you might have some problems along the way
Does everybody here run forums?? I have read VBulletin (paid) and PHPbb free, but never heard of the other options mentioned.
myBB and smf are also popular choices. And yes i run a few forums. It takes a lot of time to develop it into a good one though!
I agree whilst I use vbulletin for running my own forum I use SMF for my clients forums. huh? why? WTF? Well I use godaddy as my client server (Please note this post is about forum software NOT about your personal opinions about Godaddy which may differ!) and SMF is free to install, very fast to set up and hence as a solution for my clients it works well. I set up a fishing forum for a client last weekend. Within less than 30 mins it was set up and people were posting. SMF = zero/low cost = happy client!