i know alot (and i mean loads) about phpBB3
personally , myfastforum is a bad site to have - ok they have good modules , but the advertisements are HUGE!! personally , if u are good with phpBB also try forumotion.com
they are one of the best out there
or , if you want the simplest forum (phpBB2) then noeclue is awesome . but i just checked it and the site is currently down
if you want a very basic forum which is easy to use/run then you should try atforums.net - not the best hosting site ever , but for beginners it would be perfect
probably the fastest forum hosting ever will be on xforumsx.com - they only allow specific forums to be added , which are added manually . this stops all the bandwidth being used up therefore slowing down the forum
try any of them