My suggestion would be is to go with phpbb then switch to vbulletin. Since phpbb is simple to use and a very friendly user environment. One of many top boards uses phpbb, that would be www.gaiaonline.com -
I would also recommend you first trying with p[hpbb like this - www.hiifii.com/forums
Because vbulletin is a Paid one @ 160$ so better try 1st with a free board
Yes, I am using a free version than vbulletin, but I am plannig to use simple machines. I love how it looks. The thing about phpbb is I don't think it lets you put subforums.
But it is great. I agree with how easy it is to use.