Murchu
Well-known
For casual shoting (Body + 1 lens) any bag, usually a South America Native American "Mochila" with the camera inside a plastic bag, for a trip Domke F2, two bodies, two zoom lenses, two flashes, two triggers plus a smallish tripod bag, two stands a light tripod three umbrellas (that's more than most bring but I feel perfectly ok with that unless I have to hike), if I have to hike the same stuff in a LowePro backpack, for work much more not really worth mentioning here in rigid bags.
In any case there is not just a single answer to this question. Try out few outfits and be sure the stuff is confortable for you. The only bags I would not recommend are the ones which go on one side of the body but are rigid (like ballistic nilon over a semirigid core), everything else could or could not work depending on your taste, how many lenses you bring and how heavy they are and for how long you plan to walk and on which type of terrain.
As I wrote, I have and use LowePro products and they are good quality but so far the best line for me is the Domke. It seems like those who designed all the other lines wanted to make stuff which looks cool but Domke Designers actually use their bags and take pictures (or maybe they just listen what photographers suggest to them).
GLF
Cheers, GLF. Right now, I am really just looking for a bag that will accomodate either my D300 & 16-85/ D300, 16-85 & 35mm f2/ D300, 35mm f2 & future 50mm f1.4. I like the Domke bags, but have nothing bigger than the F-5XA & F-5XB, of which I find anything more than a body and lens, or body and two light lenses, I find more than I want to carry. Not sure how other folks manage with so much kit in a shoulder bag, I think my left shoulder would go on strike, lol.