Manufacturers -
5.11 (Royal Robbins)---------------------------http://www.511tactical.com/
ACR Electronics, Inc.--------------------------http://www.acrelectronics.com/
Alta Industries--------------------------------http://www.altaindustries.com/
Camelbak---------------------------------------http://www.camelbak.com/
CSM Tactical-----------------------------------http://www.csmgear.com/
Eagle Industries-------------------------------http://www.eagleindustries.com/
Electro Optic Technologies (EOTech)------------http://www.eotech-inc.com/
Eye Safety Systems, Inc. (ESS)-----------------http://www.essgoggles.com/
Fire Brigade MFG Inc.--------------------------http://www.firebrigademfg.com/
Fun Meter--------------------------------------http://www.fun-meter.com/
Gemtech----------------------------------------http://www.gem-tech.com/
High Speed Gear Inc. (HSGI)--------------------http://www.hsgi.us/
ICOM America, Inc.-----------------------------http://www.icomamerica.com/
Night Vision Equipment Company (NVEC)----------http://www.nvec-night-vision.com/
Paraclete Armor & Equipment--------------------http://www.paracletearmor.com/
Peltor-----------------------------------------http://www.peltor.se/
Polarmax---------------------------------------http://www.polarmax.com/
Pryme------------------------------------------http://www.pryme.com/
Recce Gear-------------------------------------http://www.reccegear.com/
Rite In The Rain-------------------------------http://www.riteintherain.com/
Safariland Ltd.--------------------------------http://www.safariland.com/
Smith & Wesson (S&W)---------------------------http://www.smith-wesson.com/
Southwest Motorsports Enterprises Inc. (SWMS)--http://www.southwestmotorsports.com/
Special Operations Equipment (SOE)-------------http://www.soegear.com/
Specter Gear (CQB Solutions)-------------------http://www.spectergear.com/
Surefire---------------------------------------http://www.surefire.com/
Tactical Tailor--------------------------------http://www.tacticaltailor.com/
Thorlo-----------------------------------------http://www.thorlo.com/
Wellco Enterprises, Inc.-----------------------http://www.wellco.com/
Retailers -
1800 Nametape----------------------------------http://www.1800nametape.com/
Botach Tactical--------------------------------http://www.botac.com/
Bowers Tactical--------------------------------http://www.bowerstactical.com/
Diamondback Tactical---------------------------http://www.diamondbacktactical.com/
Dom's Outdoor Outfitters-----------------------http://www.domsoutdoor.com/
Global Tactical Supply, LLC--------------------http://www.globaltactical.com/
Lightfighter Tactical--------------------------http://www.lightfighter.com/
Midwest Tactical-------------------------------http://www.midwesttactical.com/
Mirage Technologies----------------------------http://www.miragetechnologies.net/
Practical Tactical-----------------------------http://www.practicaltactical.net/
Strategos International------------------------http://www.strategosintl.com/
Stubby Gear------------------------------------http://www.stubbygear.com/
TJ's General Store-----------------------------http://www.tjsgeneralstore.com/
Airsoft Atlanta--------------------------------http://www.airsoftatlanta.com/
Airsoft Extreme--------------------------------http://www.airsoftextreme.com/
Full Auto--------------------------------------http://www.full-auto.org/
Only Battery Packs-----------------------------http://www.onlybatterypacks.com/
The Q Project----------------------------------http://www.theqproject.com/
UN Company-------------------------------------http://www.uncompany.com/
Wargame Club-----------------------------------http://www.wgcshop.com/
I came across this list that I had made a while back. Some of these companies might not exist anymore. Most of the retailers are reliable and most of the manufacturers make quality stuff.
EDIT - This is also only companies that make/sell stuff that I have dealt with, so its not entirely inclusive.
