One of the first heavy duty after market coolers for G80 / R600 comes from Arctic cooling. Xtreme Accelero is massive aluminum cooler, cooled by the three 80mm fans. The amount of fins it uses is impressive. The prototype has 107 of them, ant the final cooler can even have more than that. Heat is conducted by 5 heat pipes, which is also impressive.
As you can see, the base of the cooler is not only designed to cool the GPU, it cools the memory as well.
The cooler is made out of the two smaller coolers that are connected via heat pipes. The only problem that AC is trying to solve is how to balance the weight distribution of the cooler.