you can get PhpBBFM www.PhpBBFM.net FULLY MODDED !! comes stock with every mod u can get

also Invision Power Board 1.3 is free the rest + are licenced only.

then PunBB which is pretty good..

also a new one thats jsut come out.. i've forgotten the name of it.. SW somthign..

and vBulliten

thats it all i know of..