Terapad (
http://www.terapad.com/) but I'm biased, obviously ;-D
I'll give a few reasons: Terapad.com features start where the other 'pure' blogging platforms stop. For example, it starts as simple as a fully-featured blog, but can also be expanded in seconds with a built in online shop, CMS, discussion forums, image gallery, even HR tools.
It's a hosted solution so it's not going to fit the needs of the ultra-geeky linux expert who want to run his own server or slap his own code on it. On the other hand I think hosted solutions are ideal for people who want the stability of a server monitored 24/7 without the cost or the trouble (we're free).
Rather than a one-size-fit-all approach, we give people and companies the freedom to mix and match components that ultimately define their unique identities, regardless of size. A CSS-control layout insures that any look and feel can be utilized. You can also use your own domain, of course.
Needless to say, considering the scope of our product the features are too numerous to list. But of course blog pings, page protection, meta tags editions, versionning, audit trail etc... it's all here if the user needs it.
Anyway, give us a try if you can. We're driven 100% by user feedback, so feel free to let us know what you think.
Cheers!