The Simple Office bag from Qwstion is an excellent convertible briefcase/backpack with organization and aesthetics that fit many modern city folks.
Other Bags to Check Out:
The Core Pack from Topo is a classic daily carry bag with solid organization and materials at an extremely affordable price.
The ATD1 is an expandable backpack you can use for both travel and daily carry. Looks pretty damn good too. One of the best in this category for sure.
A simple, no bullshit daypack with just enough pockets and organization for modern life.
The Aer Duffel Pack is not the tool for every job, but for particular uses it just might be perfect for you.
The Weekender Meeting bag from North St. is an excellent little slimline daily carry bag. Built by hand in Portland, OR, with great materials. Attaches to the larger Weekender Travel Bag.