I carry a Domke F-2 Original (actually, a 30-year old version of the current model) with many patches and repairs on it. But I carry a C220 body, 3 lenses, prism finder, L-bracket, SBC Luna Pro meter and either a 35-mm rangefinder or a folding 120 shooter, plus all the film & filters I need. It has sufficient room for all this and is not over-stuffed. Perhaps because I have had it for so long I can get stuff in and out with my eyes closed, and I will probably use it until it can no longer be repaired. The only problem I have as I get older is that it take more energy to lug all this stuff around... and getting older is not likely to change.
I use the Lowepro Mini Trekker as well. I carry a Pentax 67 with 55mm lens attached. I also carry a 105mm and a 150mm lens, an extra viewfinder as well as a pentax spotmeter. I also carry a holga for those special shots. I have room for a bunch of filters, film, etc. The bag has held up very well and isn't as heavy as I thought it would be!!
I use a Lowepro Omni Trekker. It holds my Bronica body, prism and 80mm lens attached, four other lenses, a spare back, meter, filters, film and all the other usual suspects. It fits snugly inside a Pelican 1550 so I can check my gear when I travel, though I've never been stopped from carrying the Omni-Trekker on.
I don't like backpacks at all, so I've cut off all the straps that make it dual-purpose, and I've replaced the main strap with an Op-Tech . The bag has two major advantages as far as I'm concerned. First everything is stored on one level- there's no lifting stuff out to get at something else which I think is an enormous plus. Then there's the fact that its about 2lb lighter than the Magnum AW I used to use but seems to protect things well enough. A combination of lighter weight and slim configuration means the weight is all close to your body and easier to carry.
They're about £100 mail order in the UK- I think about $130 or so in the USA.