Arc’teryx
Granville 20 Backpack
$250, arcteryx.com
With the 20-l Granville pack by Arc’teryx, you can haul the gear you need as you head around town on your commuter. It’s water-resistant, so a 15" laptop sitting in the bag’s internal sleeve will be well protected from the elements. Under the main flap, there’s a zipped opening to the main compartment, which means everything inside stays secure. Attach a rear light to the bag’s clip-in point before you head out at night.