Without knowing you, your fitness level, and what you plan to carry, it's hard for me to make a suggestion as to a specific pack. What I can do is share with you some manufacturers that I've had good luck with.

• At the EDCForums store, the SERT backpack. I'd share the link but they're out of stock. I wrote a review of the backpack at http://edcforums.com/threads/first-impressions-of-sert-in-route-edc-backpack.121655/.
• Goruck. I own two and they're fantastic -- my GR1 has been with me for countless air, road and trail miles and could easily be mistaken for new.
• CamelBak's Military and other packs. I've owned several and they've been excellent. My older (discontinued) M.U.L.E. is my range pack and I have not been gentle with it, but it looks new. I recently got a screaming deal on a discontinued Mil Tac H.A.W.G. and so far I'm super happy with it.
• On the much, much lower end we have a few L.A. Police Gear 3 Day Backpacks and "Operator" Backpacks and they've been surprisingly good at that price point.

There are others out there that have really good reputations like 5.11, TAD, Tom Bihn, Kifaru and Mystery Ranch. If I were in the market for a new bag I would consider any of these as being high quality, but I don't have significant hands-on with them.

For me, based on my personal likes, dislikes and experience, Goruck is what I would buy.