Well are you looking for a traditional blog, or a social-networking site with blog capabilities?
Blogspot/Blogger is what I use for hardcore blogging, though I don't do it very much. Really easy to use, customizable if you are into code and stuff. Livejournal is also pretty sweet; I never had one but enjoyed looking at my friends'. I deleted my MySpace though, once I got a Facebook page... it's gotten way too spammy as of late.