Presently I own
A dutch army sting, which is pretty good, but not perfect
A vintage Vango, which is as heavy and hard wearing as the sting, arguably more comfortable, but not as capacious as the sting, it is my BOB with room to spare to bung my laptop in if I have to make a quick exit.
A vaude whatever, has an external frame, which is the most comfortable but the shape is wrong for bulky loads, holds about 25 ltr's
A BCB patrol pack, again about 25 ltrs, not as comfortable as the vaude, but carries bulky stuff more easily. Not a very good pack quality wise though, I have had to repair it, however it does mostly for shopping these days
A webtex bergen, the less said about it the better, utter rubbish, I use it for storage
A vintage even more vintage than my vango cobmaster external frame pack (who remembers them) why did they go out of fashion, you can strap anything to it, although the suspension system leaves a lot to be desired
A stuffable 15 ltr day pack from Kathmandu (the store not the town) which arguably sees more use than any other of my bags as a general bimble bag.
I have had more than that in my time including two proper Bergans of norway Bergans, which I never should have got rid of really but I considered the frames excessively heavy and the canvas prone to rot.
The best rucksack of all is the one I do not yet own, I haver much between vintage and the advantages of modern lightweight technology. I have in the past made two of my own rucksacks, one of which was so good the guy who burgled my flat filled it to the brim with my goodies and took it with him as he abseiled from my fourth floor window on the flex he had cut from my vax vacuum cleaner using my John Nowill bowie presumably which also went with him.