Crumpler Cupcake Full - £95 (about $150)
Seemingly taking its design cues from a turtle, the Crumpler Cupcake Full is, design-wise at least, a very well-rounded affair. The upside of this is minimal risk of catching the edges of the bag on people or objects in the close quarters combat of a rush-hour commute.
The downside is that, even in this 'full photo' version where all of the main section is given over to camera kit, stowage space is quite shallow around the sides and top of the main compartment. Even so, you can squeeze in a large 70-200mm f/2.8 lens along with your camera and kit lens, plus a further couple of lenses and a flashgun.
There's no slip-on rain cover, but Crumpler's '1000d Chicken Tex Supreme hyper performance fabric' is tough and very shower-resistant, and there's also a waterproof internal lining. Access to all compartments, including camera and laptop sections, plus two organiser pockets, is via a single zip that runs around the back of the bag.
A secondary mesh cover zips over the camera section, to minimise the risk of camera kit falling out accidentally, although this does reduce access speed. All in all, the Crumpler Cupcake Full is a well enough constructed backpack, but its outright volume unfortunately ends up being compromised by that curvaceous design.