I agree; phpBB is very good. There are many templates/layouts/color schemes, lots of customization options, you can choose how much control you want to enforce, etc. And it was easy to set up, too.
If you want to see an example of it (running at DreamHost), see http://erebaltor.dk/forum/ (sorry, text is in Danish).
Try out DreamHost with a free WebID -- Prices, options