I currently have a LowePro Protactic 450AW II, which is quite nice and transports a decent amount of gear plus things to eat and drink. Their strap system where you can attach additional thingies on the outside is also quite nice. Works for example great to carry of playground toys around as well when i go there with the kid ;-)
All in all it works well for anything up to maybe 2-3h walks, but would not be good for longer hikes. Also it’s look might definitely not be for everyone.
So i was wondering what other people have, like and dislike about that.

I have a Thinktank Backstory 15, a great and tough backback.
In the past I used a small Thinktank retrospective 5 shoulder bag, great bag, but too small now.
Then I got a big Thinktank Retrospective 30 as I needed to carry a laptop on a trip, it is too big, but I love the water bottle holder which can accept a water bottle being dropped into it without fiddling with elastic. Sadly the canvas was not very tough, and even after a few months there were big holes where it had been worn away by nothing more than rubbing against my jacket/pants when it hung over my shoulder.