Oh, let's get nerdy!
In a stunning blaze of irony, while Tubus racks must be ordered through the Ortlieb USA distributor and are frequently backordered, Ortlieb panniers must be ordered through NRG Distribution. Both Tubus and Ortlieb are the pinnacle of quality touring gear, with Surly Nice Racks running a distant second due to their sheer overkill factor. The Nice Racks also pale in comparison to Tubus when it comes to ease of installation. Nitto stuff is quite pretty, but often even harder to source than Tubus unless you order direct from Rivendell, and Nitto Big Racks have half the load rating of Tubus. Tubus hardware is second to none.
Regardless of manufacturer, remember that in the field, it's far easier to find someone who can repair chromoly racks than aluminum ones, and aluminum can and will break at the most inopportune moment.
In the shop, we consider Ortliebs to be the only truly Wet Coast-proof panniers on the market. Fully seam-welded, no zippers to leak, massive capacity, and you've really got to be beating on them to get even the lower mount to budge on the rack. Carradice bags are lovely indeed, but I'd be hesitant to subject waxed cotton duck to a 10-hour rainfest.
I've toured with both BOB's and a TubLieb setup, and will never, ever use the former again. I found that on Sunshine Coast and Gulf Islands rolling terrain, the BOB acts like a massive pendulum out back that prevents you from ever standing up on the bike, and the resultant speed wobbles prevent you from gaining any momentum on downhills. With all the weight low on the bike itself via racks and panniers, you can really open it up on downhill sections.
Touring tires? My girlfriend and I are loving our Schwalbe Marathons. There seems to be a recurring theme here: Germans make awesome touring stuff. I really like the natural rubber compounds that Schwalbe and Continental use. The Marathon Plus carries a huge weight penalty, though, and seems to be overkill. Don't let anyone sell you on any Rivendellesque Panaracer-made tire for touring - they ride very well, but that's due to near-translucent sidewalls that are more randonneur/pass hunter-oriented and are nowhere near rugged enough for real touring.