My CamelBak. It is without equal in usefulness for all the outdoor stuff I do; cycling, hiking, running, out-and-about-"ing". I don't like the arrangement for securing the tube and bite-valve while the pack is in use. You must either accept the springy damn thing ricocheting all over the place or use the too-tight bands to anchor it in place which takes way too much time to secure and de-secure and often forces the valve off the tube. Still, it's hands down the best gear I have. (Good warranty, too. A zipper broke and they replaced it, no problem, although it was up to me to keep the conversation going. I had to follow up on each point in the transaction.)