MSR, Marmot, OR, BD, Sierra Designs and Julbo, to name a few. I've sent some pretty mangled glacier glasses back to Julbo a few times and they have always sent me a brand new pair. Smith has hooked me up a few times but not always. I still really like Smith sunglasses though. I also really like Kershaw knifes. They have replaced a ton of folding knives that have gotten the tip broken off or other minor damage. They make a great product too. It never hurts to send a nice schmoozy letter telling them how great they are before hitting them up with any warranty request.