My favorite would be Problogger, i've learnt a lot from there.
Even DBT rocks, but sometimes he just posts for the heck of it as he has to update it daily. But i must say I have had many Q's answered very well by Daniel.
Blogussion is also up and coming.
As for their future...1,000's of new blogs are created daily. These blogs have a lot of scope ahead.
As Farrhad said they have a lot of scope. Traffic may keep coming in but ideas may fall short.
My favorite is StandOutBlogger.
I think on the long run these bloggers will run out of ideas.
Actually, I have no favorite. It is because their quality and benefits of articles is not consistent (to me), so it varies.
But if you insist, here are my top 3 favs, ranked by how much they've helped me.
I really read many of these blogs.
Copyblogger is my favorite. I love his writing style.
There is a lot of scope for these blogs IMO.
The only one I really read is problogger but I've read a few more recently like Teenius and Blogussion.