The Swifthech H320 is current the king but most people don't know of it (it's a 360mm all in one liquid cooler that has been ooyt for a while now). Others that follow st why Kraken X61, Noctua NH-D15, Swiftech h220x, and Kraken X-41 (the the high end phanteks cooler is also great).
Custom loop kits with instructions and everything from XSPC are a great choice as the 360mm kits from them will beat everything.