I used Arctic Silver Ceramique on mine. I believe they changed the name of it to CMQ-22 or something like that. It did slightly better on my CPU than Arctic Silver 5, so I tried it out on my GPU. Originally, my stock fan speeds kept the temperatures at around 82C at idle, and at load it didn't get over 90 due to the fan kicking in. After the Ceramique application, done via the credit card thin coat method, it was about 8-10C less, which is pretty good. At the moment, the fan speed is set at 45%, and I am getting roughly 43-45C at idle, and 55C at maximum load.
I did have a Thermalright HR-03 GT waiting on the side, but with temperatures like this it doesn't seem necessary. Better the hot air is pushed out of the case with a dual slot cooler than being blown around inside the case anyway.