Most high-end companies have great replacement programs for gear that fails even if it is several years old. It is good to hear about companies that also replace gear that has been destroyed due to a customer's fault, so thanks for sharing.
Aside from the companies that have been mentioned, I have had good success with Arc Teryx. Additionally, Osprey's official policy is to repair or replace any Osprey pack from any date even if you bought it on Ebay, at a garage sale, etc.
Smith is pretty notorious for poor replacement options (especially compared to Native).
I've always had excellent customer experience with Mountain Equipment Co-op (MEC). They definitely stand behind their products and have a <a href="http://www.mec.ca/Main/content_text.jsp?FOLDER%3C%3Efolder_id=2534374302881722&bmUID=1268757812040">Rock Solid Guarantee</a> policy.
Had a Princeton Tec Aurora 3-LED headlamp which was ~6 years old and had been on numerous adventures. Recently I noticed one of the LED's wasn't illuminating and there was a rattling sound. The headlamp was still usable, but I sent them an email.
They replied that the headlamp had a lifetime warranty and issued me an RMA number, so I sent it back. A couple weeks later I received a brand new one in the mail. I didn't know they still made them, but the instructions said (c) 2010. Apparently the new one uses more efficient LED's, rated to 35 lumens. Cool.