My go-to pack is a simple camelback rim runner daypack. Nothing fancy and cost me about $80 about 3 years ago. It has gone with me on long trail runs (20+ miles) in the summer and doubles as my 7 year-old's backpack when backpacking. It's durable & holds all I usually need for a day. I use outside attachment points for strapping clothing layers on it in the afternoon. I can fit lunch, dinner, snacks, first aid, water, filter, foam seat, 50' paracord & basic essentials (spare nocks, sharpener, etc.) and raingear inside. It isn't quiet material but it's the first thing I ditch if I'm starting a stalk. I'll throw it in the car for family trips so I can haul food, water, clothing for everybody without having to track kids' water bottles & such. My wife steals it whenever I'm not using it -- sometimes just for taking the kids to the zoo.
The last couple hunts I've done I left the backpack and brought a simple canvas messenger bag. It's quieter against the brush but since it rides more on the side, it hits the brush more often. I like that the main compartment can be accessed without using a zipper, though. I got busted last year while zipping up a pack & wanted to give it a try. It worked okay. I'll probably go back to the camelback, though.
I know some people really get into their gear. But for me, I prefer to keep things simple. I use my gear a lot throughout the year for many different purposes and hate having to buy and store things that only get used a few times each year. I spent good money on my ultra-light frame pack for backpacking and have used that for hunting as well. I've looked at quieter "hunting" packs but they're always heavier, lower quality or cost 2-5x what I already have (and still weigh more). I prefer to keep things fairly light while I'm out and just hoof it back to the car if I need a bigger pack to get something out (a rare event anyway). I keep going back to my simple camelback & will probably use it until I wear some holes in it.