Osprey Vertigo 40

This is a fantastic, durable pack. Easy access - no digging around for stuff, just zip open the front and your good. You sacrifice weight for durability, but if you can then it's worth it. Easy to even out weight in this pack with the easy entry. Bladder is inside the pack itself, not outside of the internal frame, between the padding so it doesn't interfere with the design and airflow. Simple, functional & durable.