I currently use a Timbuk 2 messenger bag which I really like the build of, durable materials and a nice choice of sizes, colors, ect.
For my daily carry I generally just carry one camera and a lens wrapped in a padded wrap.
For outings where I want more gear Ill generally throw in the padded insert from a previous bag I had.
They make a large variety of color, size, ect. combos for the above two links and there are multiple manufacturers available.
The combination these two allows you to have a pretty flexible setup and get the bag you like. I looked at a lot of camera bags and couldn't find one that was pretty light, had enough flexibility and wasn't some stupid combo of colors.