XSPC RayStorm Pro Twin D5 RX360 V3 WaterCooling Kit
If you have an Intel CPU, then this is a great option, but that limitation keeps it from being the absolute best choice on the market. The reservoir is easy to use and watertight, the pump works effectively, and it all connects to the waterblock that you can easily install onto your CPU. There are three 120mm fans that come with this setup, which gives you great cooling and ventilation. It includes about six feet of hose for set-up, and even includes thermal paste for installing the CPU water block on your processor. XSPC provides white and blue LEDs on this kit for a clean, sleek look and it's designed to work with multi-core CPUs for optimal cooling performance.