We have tried. Vbulletin, Phpbb, XMB Forums, Ikonboard and Invision board, but personally, we find that Invision is better.
Invision board has many features similar to Vbulletin.
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If you have the money to spend i would recomend Vbulletin, but if your short on change phpBB is an excellent forum software. I use it on several sites, and i really enjoy working with it. Quik and easy installation as well.
Links since noone else included any
Vbulletin - $160 for owned license (unlimited time for 1 server 1 site) and 85$ for leased license (1 server 1 site for 1 year) http://www.vbulletin.com/