Favorite blog and wiki platforms or sites?

Here is one more question to prompt reader participation in my upcoming presentations…

In the wake of the OCDE blocking access to blogger (for what turns out to be half of the districts in the county), I am very interested in presenting alternatives. I am focusing on edublogs.org and learnerblogs.org, which are based on WordPress, but I am also mentioning novemberlearning.com, which recently underwent an overhaul, and classblogmeister.com. There are so many others as I’m discovering… but I wonder what you all are using. So, what are your favorite blog (or wiki) platforms or sites?

Thanks for your input. :)