An old and familiar list - ranked by order of post count numbers.

And IMO emphasises why forums outstrip blogs as a community marketing tool.

Blogs have been far too over-rated for too long as a community building experience. They're not better - they're just easier to set-up for newbies. Forums, on the other hand, take a lot more momentum to take off - but when they do, they cannot be matched in terms of audience reach.

2c.