Honestly, bags are the hardest things to choose. I had a Lowepro Slingshot and didn't like the way it works at all so I sold it and replaced it with something else which I can't remember. Whatever that was it also didn't last more than 6 months before I sold it.
As I said above, I've had 2 Crumpler shoulder bags and they were both excellent. Well made, rugged and hard wearing and they look pretty cool as well. I've not had one of their rucksacks but I imagine they're as well made.
Tamrac are good quality and very good value for money but ended up with the Kata DR-465 backpack. They've just released a new one (called the DR-465i) which has a tripod mount on it as well. Kata's own pages on it are
here and (just for reference)
this is the WEx page.