I have a Deuter ACT Lite 65+10. Mainly because my wife got a Deuter Kid Comfort III and I decided to try the same brand. We may have both gotten larger models than required, though...
Try to find an rei garage sale. I picked up the kelty cosmic down 40 for $38 and they had an igneo for $99 which is normally closer to $300. Down saves a good bit of weight and pack room, it is also supposed to last longer but I haven't owned anything down for more than a season yet (but its all still good).
I have an Osprey Atmos 65 AG EX (small) for when I backpack with the kids... Love it...very comfy. I have an Exos 58 (medium) for solo hikes...and it is the one I plan to bring on the Trail. I'm learning to cut back on what I bring...finally think I can make the whole AT with the Exos.
Planning for a North-South thru-hike to begin...one of these days...
Can't go wrong the ULA Circuit. It has been good to me.