You have a few options, but they depend on case and ram heatsink height. If you have high ram heatsinks and your case has a rear 120mm fan, you are going to wants something like a Cooler Master Seidon 120XL or a Corsair H80i. You can go cheaper, if you don't have high ram heatsinks, with a CM Hyper 212 Evo, but it could be too tall for your case. A hyper TX3 is the cheapest solution and will cool better than stock, but not as well as the other 2 options. As a side note, my Gskill ripjaws just barely fit with my Hyper 212 plus.