I am looking for opinions on the best forums available. We are currently using PHPBB which seems OK but I would like to see a few more features and options.
We get 2 to 5 new bogus members every day most of them advertising drugs and sex. We have enabled email verificaton and the image that you type in to prevent bots but I would like to see more security options.
I also like the feel of forums like Vbulliten more but I wanted to see what every ones thoughts were on different options.

So what are the best open source forums and what are the best forums that you need to pay for.

I prefer IPB forums.. however the license is about $70 a year. To me it's worth it for the options.

I run another forum for some authors..and they don't want to pay..so we use phpBB. It's ok..but since I'm used to IPB .. I get frustrated not being able to do certain things.

I use phpbb gonna try vbulletin soon.

I am currently using a free forum through forumer.com its a free IPB forum and tbh i like it alot better than the free phpbb one, alot more to deal with in the admin area but great and nice clean layout, you do have a little advertising but nothing major and you do have the choice of advertising on your forum and making a little money on it, i haven't looked into this part fully yet