What makes a good blog?

During my run yesterday (which was miserable, by the way; thanks for nothing heartburn), I was thinking about blogging. Why do we write blogs? Is it just a way to tell people about our daily lives? Is it a call for attention? Is there something else? And what makes a good blog? Is it the topic, the way the blog is written, the blogger's skill at telling stories?

I've read a variety of different blogs for a number of years and the ones that interested me the most were the ones that talked about a specific topic I was interested in (mostly, gaming; more specifically, WoW). Some people just wrote about their experiences, some set out to prove things, some gave advice, some tried to carry on a conversation with you, others just asked a question at the end of their blog. I'm not sure there's any one style that was more entertaining to me or made me want to comment.

I suppose the real reason I was thinking about it last night is that, reflecting on the types of posts I've been making, it seems a lot like I'm simply talking at someone rather than trying to include them in a conversation. Does that matter? I have no idea. Shoot, I haven't even sent this blog to anyone, so it's not like I'm actively trying to build a reader base, but still ... you have to wonder (or I do) how long I will continue to blog if it's just me writing an online diary. Right?

I actually think that blogging about my return to WoW would be fairly interesting, and I plan on doing a weekly post about my fitness progress (if for nothing else, it will keep me motivated). Other topics though? No idea! Does anyone really want to read my rambling about fantasy sports? Maybe not, but who knows!

What do you think makes a good blog? (see, I'm learning already! including a question at the end, what a pro)