I've updated my original post to include some more recent examples as well as make some things more easily read. (The gist is the same)
Additional things that do not fit into the original article -
Boots
Gloves
Kneepads
Boots should be pretty obvious. Most good ones are made out of leather and cordura or the like and they're thick enough to shrug off most thorns and other pokies you'll find.
Gloves and kneepads are something that I've always worn when playing airsoft and I can't see myself doing so without them.
I have what I think are the nicest gloves out there. They're expensive for gloves, but they work great for me. I haven't had any kind of problems with them since I've had them and though I'm a bit less dexterous than I would be without them, I feel that the trade off is quite worth it. If your gloves get torn up, at least its them rather than your hands. The ability to touch/interact with pokey, hot, dirty, or stuff that would otherwise hurt your hands is invaluable. Crossing a fence, getting in a vehicle, etc. make it worth having nice gloves, I think.
I consider kneepads to be essential as well. The one or two times I've not worn them, I've regretted it, even in a short game. Aside from the usual cactus/pokey protection, they allow you to somewhat comfortably take a knee or monica position for an extended period of time.
I'm not too keen on elbow pads. I'm sure they have place, and getting your elbows messed up does suck, but for me, they've only really been in the way.
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Also, here is a list of specifically what I use now and some comments on them -
Eyewear -Oakley SI M Frame 2.0
Bolle T-800 Goggles
While I don't wish to discuss sealed vs non sealed eyewear here, I will talk about glasses. I feel that the Oakley M Frame and M Frame 2.0s that I wear now provide an adequate degree of protection for me. When you get down to it, everything is a compromise and everything in what we do is a calculated risk. This is no different. I've had fogging problems before and one of my solutions to that has been the Oakley M Frame. I take the responsibility of knowing that I have the perhaps slightly reduced protection of glasses to have the greater visibility that they afford me. End of story on that one.
The Bolle T-800s are my current favorite goggle. I've had none of the same fogging issues that I've had with other goggles, including the ESS Turbofans. Not really too much else to be said about them.
Undershirt -PolarMAX All Year Undergear T-Shirt
I've had these for a couple of years now and they're starting to pill and I think their wicking effectiveness has been reduced. I plan to replace them with some 5.11 or Zensah undershirts.
Load Carriage -Coyote Tactical Mesh Chest Rig
Coyote Tactical Kydex Single M4 Magazine Pouch (x2)
Coyote Tactical Dual M4 Magazine Pouch (x3)
Coyote Tactical Mockingbird ICOM F4S Radio Pouch (x2)
Coyote Tactical Chuckwalla Utility Pouch
Most of the commentary I have on these items can be found in the initial post in this thread.
Hydration -Camelbak 3L Thermobak Omega
Its simple, compact and does the job I want it to. An added bonus is that because of how the zipper is, I can route the drink tube under my arm, rather than over my shoulder. I prefer this way, as it ends with the drink tube pointing up at your head, rather than down at your feet.
Gloves -Southwest Motorsports Digital Friction Fighter NT Gloves
The gloves I mention above are these. They're definately some of the more expensive gloves out there, but I feel they are the best for me. Before these, I used Hatch Operator gloves. I really like the Hatch Operators, but the SWMS Friction Fighters blow them out of the water. They are less dexterous, but far, far more stout. With Southwest Motorsports' absorption into Camelbak, I think the availability of these has been reduced and the cost has likely increased, but I'm not sure.
Kneepads -Alta Industries Superflex Knee Pads w/Altalok Buckle
The final word in kneepads. They look the same as the Hatch, Blackhawk, etc ones, but they are much, much nicer. Unlike some of the others, they stay where you put them and don't bite into your legs. $5-10 more than other brands, but in my opinion definately worth it.
Socks -Thorlo Combat Boot Sock
These socks are the best I've found, though I've not looked very hard for socks.
Nice and thick where it seems to matter, they've not given me a problem. They're expensive for socks, but I've had the same ones for a long time now.
Boots -Wellco Value Cool Lite Infantry Combat Boots (VCL ICB)
I've not had any problems with these boots in the nearly 5 years I've used them. Since I really only use them for airsoft and the occasional hike, they've held up just fine. I think that the quality of Wellco materials and workmanship has declined since I purchased these, so I don't think I'd buy the same thing again when I finally do need new boots.
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I hope to continue to expand this thread with pertinent information.