Outdoor Products 4304 OP-GRA-005 Op Iceberg Hydration Pack, Graphite

It's pretty comfortable. Several pockets store other items without adding too much bulk. It seems durable enough. For the size of the pack, I'd like a larger bladder, but it's 2 liters, so I'm probably asking too much. Besides, you could feasible carry two one-liter bottles in the pack with the bladder. It's pretty roomy. I don't like to have to suck on the bite valve to get water, but maybe they're all that way. Sometimes the valve will dribble a bit if not turned upward and clipped. My biggest complaint is that I'm having trouble finding a replacement valve. It's a screw-on type. [...] so the jury's still out.

Very comfortable, easy to use, good fluid and decent storage capacities. Snapped open storage area not as useful as I would like, but good storage space overall, especially for the price.