i think PhpBb is the best choice if you don't wanna pay fee.
If you have alot of money, should VBB
I don't think it's worth the money to get a paid forum.
P.s. Nor do I want any of those nulled scripts. :@
I would personally just go for MyBB. It's free and very easy to use.
mybb is the number one out there unless u want to drop cash then we can talk