What type of camera bag is best?

I'm looking at purchasing a camera bag (I got one of those comes-with-the-camera bags http://i.imgur.com/rrSp7.jpg and I really dislike it).

My question to you all is do you prefer a messenger, backpack, or sling style camera bag? And why?

I've heard messenger are the best style as they're easiest to remove your camera from.

If you do have a favorite, please share. I'm looking for one that will accommodate a DSLR, a couple lenses (think at least one prime and a zoom), and a laptop.