For a backpack - go and try them on with weight. They all fit a little differently.
For gear, the more you pay the better it can get
I have a marmot ultralight tent and really like it.
I also always carry a knife, lighter/matches, and a good flashlight. I recommend Zebralight for a good all around flashlight.
A nice inflatable sleeping pad is also something that shouldn't be overlooked, worth the space and weight IMO.