Secure and easy to maintain forum script suggestions?

[crunch42]

Anyone have any suggestions for a forum script that is secure (built with security in mind and constantly updated), and easy for mods to maintain (one-click deletion of spam and spam accounts). I see this forum is vbulletin, so that's presumably one option. Doesn't have to be free, but does have to be php/mysql.

[AndrewT]

As far as security is concerned, all of the major ones have had their fair share of gaping security holes but they're all pretty good about patching them quickly.

I would suggest demoing each option and see what you prefer. I've only personally spent any real amount of time with vBulletin so I can't really comment on the others, but I can only imagine there must be something better out there. Now it is just convenient for us to stick with it more than anything