I've purchased from Yesgamers a few times, bought a rune or two, and a few annihilus. I got my items within minutes. The functionality of the site is great, it's easy to use and they offer so much more than they need to. I purchased their anni promo (4x anni for 1.44 us dollars) and was redirected to a site where you see the progress they're doing with your order. After that they give you a free mule service in which you just press buttons in the browser, and can command the characters to drop the purchased items!
To sum it up, this site does a lot for you as a customer. They respond quickly to your emails, they deliver very fast and offer great prices for various items (including hardcore items.)