I like phpBB2 best! I think that this one is best because it has sooo many mods out for it, and because ive spent so much time modding it i find it really easy to program my own mods if no-one else already has made one :P

Also, the ACP is great, if a litle "sticky" to use....

IPB is okay too...i guess... the admin panel is very easy to understand and use....

hixy