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 Velo backpack from Rickshaw Bags is an awesome, simple bag that comes in a few different sizes.
A gorgeous messenger bag with a kind of modern urban-alpine aesthetic and absolutely lovely, dense, long-haul materials.
A very sophisticated and classy take on the classic backpack, but with modern improvements for us tech-workers.
The Wilderness Rucksack from Tanner Goods is a gorgeous, artisan, hand-shucked heirloom bag that your grandpa would be proud of (whichever one of your grandpas was more badass).
The Daylight Backpack from Tom Bihn is a workhorse of a packable daypack.