Agreed. It was the main reason I switched to Amex for all of my US (and most other countries) payments as soon as a forex free Amex was launched in the UK (Issued by Lloyds Bank, Amex themselves don't issue any fee free forex cards in the UK). It saves the hassle of DCC + Amex's USD to GBP conversion is great (usually equal or better than MC).

I do vaugely recall retailers like Toys R Us, Century 21 (In NYC), JC Penny and Macy's (Possibly) and Levis using DCC. They were all pretty easy to avoid though, the first four were done on a customer facing terminal and the Levi store used a tick box system similar to what is used in Asia. This was a couple of years ago now though.