I ordered my TimBuk2 bag in June 2011, and 8 months later I'm still impressed.
TimBuk2 has a wide selection of bags and backpacks - something for everyone. You have the option of personalizing nearly every product in their inventory, or go with a plain design (my preference, since I don't want anything too eye-popping). Most bags come in multiple sizes; good for customers with laptops large and small.
On the online store, most products have an embedded YouTube video of someone from the company handling the bag/backpack for 60 seconds and opening the pockets, so you can gauge its size. This is a surprisingly useful thing! There are also tons of user reviews on the site - both positive and critical. Being able to see what other customers like and dislike about each bag helped me narrow down my choice (and the fact the company doesn't remove negative reviews adds credibility).
Everything is handmade in San Francisco and shipping was very fast!
My Bag - the Command Messenger
I selected the Command Messenger model for its laptop pocket and for its ability to fold flat for airport security (so you don't have to take the laptop out of the bag). After taking the bag on a few flights I found it was often faster to take the laptop out anyway, rather than explain to the screeners it was a TSA-compatible bag.
The laptop pocket is bright red on the inside and the fabric has foam padding bubbles inside of it!
Inside, there is a HUGE main pocket and a handful of smaller pockets, including a pen and business card holder that could be removed (velcro). Some of the inner areas zip closed, others are open for easy grabbing. There are four outer pockets - three hiding under the velcro cover flap and one accessible through the side (perfect for house keys).
There is a secret pocket on the bottom of this bag that's perfect for laptop power bricks - the tangles of cords stay out of your way while travelling.
The bag is near-flat when empty but seems to magically expand to hold whatever I need. It's a true man-purse: you can carry things like umbrellas, light jackets, and scarves just because you can. Since the laptop pocket is separate from the main pocket, carrying a laptop doesn't really reduce your carrying capacity. I'd be able to carry a laptop and two gigantic engineering textbooks with ease.
This bag is solid. Before purchasing, I read a few reviews where a small handful of customers had bad stitching, but TimBuk2 flexed their customer service muscles and fixed or replaced them for free.
With the main velcro cover flap, it's easy to grab stuff while you've got the bag shouldered. The strap is padded and adjustable and it's just comfortable.
The one feature missing on my bag is a comfortable carrying handle. It has a handle, but it's a one-inch piece of flat seatbelt material. If the bag is even moderately filled, carrying it with the handle can be uncomfortable.
With shipping and taxes I ended up spending about $150. It was expensive, but it was a planned, well-researched decision and I've been very happy with the result for the past 8+ months, and expect it to last a few years at least. If you're in the market for a new bag, Timbuk2 has my recommendation!