I like Osprey packs. I have several in various sizes. They tend to have lower weight and better comfort for any given capacity in my experience. Their Aether 60 is a classic. They have smaller, more technical mountaineering packs too, in 28, 37, and 52 liters. And really big ones. I used their Aether 85 on a trip to Aconcagua last year and it worked out really well.
I have an older Osprey pack I like, but the last couple of packs I've purchased have been Go-Lite packs and I've been really happy with them. Go-Lite has come a long way over the last few years - the packs they are making these days are pretty comfortable and durable as well as being lightweight.
Osprey wins hands down for me. The custom formed hit belt is very comfortable and they have a wide range of models. I have the Anether 60 too and it is amazing. Also, their day packs are just as amazing.
Yea, I just bought an osprey atmos and though it has a few issues I'm having to adjust to concerning packing and the hip pockets on the small 35 being hard to access, it is probably the most comforatable pack I've worn.