i'd recommend Pac Designs. many messenger bags, incl timbuk2 and chrome have a tendency to 'flatten' out on your back when you put oversized items into it, due to the positioning of the straps at the ends of the bag. the Pac Design bag is designed to curve around your body, and it never feels weird with any sized items in it. one of my friends bought the Pac bag, and i tried it and i've been riding for years with a timbuk2, and it was like heaven. the Pac unfortunately is significantly pricier than most messenger bags but if u have the money u won't be disappointed. it doesn't really have a lot of the 'flash' of the chrome or timbuk2s but it's a solidly constructed, extremely practical bag.

aloha,
matt