If we are talking about closed water coolers then stick with the Hyper 212 evo. If you seek more cooling then consider the Noctua DH-14, its quite big but if you have the computer case then you should go for it since it performs on par with the H100 which is one of the best pre-made water coolers.
Edit: Forgot to say that the DH-14 is an air cooler. Generally air coolers are more safe than water coolers since they don't leak and that you don't need to hear any pump noise or in my case the slightly annoying air whizzing through the radiator noise :lol: