I have used so many it's pathetic....
Here is my current setup...
Lowepro S&F reporter 200
Lowepro S&F Lens cases 1W and 4
Lowepro S&F S&F bottle bag, and memory wallet
Lowepro S&F Pouch 60
This KIT allows me to carry the D1x with L-bracket attached, the SB800, 24-70mm f2.8, 17-35mm f2.8, 60mm f2.8, 80-200f2.8, 300mm f4, batteries, fileters, accessories, and a light meter. However IF I want to carry everything, it becomes a bit awkward.
So I also have a Lowepro Nature Trekker, and if I need to carry everything, I generally go with that.
Other bags I have include Photoflex Hip Bag (Galen), Tamrac backpack (still has my hassy in it) Pelican hard case (used for weddings/events along with soft bags), lowepro topload zoom (nice for sking), and the lowepro orion AW (hip bag that has a daypack on top).
I should likely sell some of this stuff!!!
The way I generally work is to put everything between the backpack, and the 200AW. Then I swap lens cases, lenses, and accessories as I go based on what I think I will be shooting. I leave the rest where ever, trunk, house, etc..
One reason I purchased the S&F system is I wanted a system, not one bag. I've discovered one bag is never going to be enough. It's either too big, or too small, or hard to carry loaded down. The S&F system is modular, and so one can add and subtract lens cases and pouches to meet the current shooting needs.
A big pack like the trekker is nice to have when you want to carry everything, but I've found that is rarely what I want to do. I sometimes regret leaving lenses behind, but more often, I take four lenses, and end up using two....
Ron