Patagonia is a company that makes and sells clothing and equipment for nearly all outdoor activities. It is well-regarded among outdoor enthusiasts and yes, fairly expensive.
Patagonia holds the trademark on Capilene and Regulator and also uses many high-tech fabrics as well as the good old reliable down and wool. Patagonia insists that all the clothing that they make be of top quality in function as well as form.
Patagonia, like many of the big out-door suppliers and retailors, is involved in environmental activism -- donating 10% of profits to grassroots environmental groups.