Timbuk2 classic in medium. It's not waterproof, but it's fairly water resistant. I used to commute with it, Laptop, charger, change of clothes, lunch, some misc stuff. I still ride with it now and again, so I can ride in road shoes and put sandals in the bag, so I can change when I get somewhere. It's great. I use it pretty often when I'm traveling too, I love having it swing around and be accessible.