What bag I use depends on what I'm doing, and how.
I have yet to make the jump to Petrol, which many recordists prefer, so I'm still rockin' the Portabrace AR-7 like @sepulchra. I like having the wireless pouch mounted on it for the bits and bobs needed in the field, even if there's no wireless involved. The velcro is definitely not stealthy. I sometimes carry it on my chest using a LowePro-brand chest harness for the TopLoader series...unlike production audio harnesses like the Versa-Flexes, there is no padding on that harness, allowing it to be worn under any backpack.
As per @Ryan's comment/plug, I do use Maxpedition brand bags for more stealthy carry in urban areas, specifially the Lunada and the Sitka. I've come to like the Sitka better, because it's designed to swing around the body and be opened while horizontal, and it's a better size for carrying more of a day's worth of clothing, food, and so forth. I also use my old, beat-up Chrome messenger bag sometimes when I need to carry mics, a windscreen, and the recorder in the same bag while keeping a low profile. The problem with messenger bags is that the flap opens towards your body, which makes keeping it open while recording a wee bit more fiddly than I usually like, but it works when the context is right.
All other times I keep all my gear in two 6'-long Pelican cases that my intern carries around on his back. Because that's heavy, I've strapped an espresso machine to his chest to balance his load, and to make those long days of field recording so much nicer for me. :-p