I have tried and owned lots of packs over the years. Believe me, a bad one will really hurt in the wilderness! My current packs are, large a Karrimor Sabre 80-100L, Medium is a Camelbak BFM and daypack is a Camelbak Talon. Each have features that I like and carry very well. The 2 Camelbacks have 100oz hydration systems and the Karrimor has more than adequate space for hydration bladders. They are all military oriented which provides some options not found on most civilian models, subdued color for one. Lots of attachment points for additional gear. The Karrimor is hard to find in the US, I bought mine off ebay but the shipping from the UK is a real negative factor.
I was really impressed with the Camelbak military products and I really love the 2 packs. Both available at discount prices online. Hope you figure out what works best for you. Cheers!