If you're looking for a messenger style bag, then you might like the Tamrac Rally Series. I think they are a good looking bag and they offer various sizes, plus the bags are well built and they have good padding.
http://www.tamrac.com/f_rally.htm
I have the ThinkTank Retrospective 20 and the Tamrac Rally 6. What I like about the Tamrac Rally series is the bags weight is 1-1.5 lbs. less than the same size bag in the Retrospective series.
When I'm walking around all day, the ThinkTank bags can start to feel heavy, so I now generally use the Tamrac Rally because it is much lighter.