Honestly, different people will tell you different things. Personally, I've used Feser One, Distilled water with biocide, Distilled with Silver, Distilled, Mayhems Pastel Blue, and now I've got Primochill ICE in my system. I typically follow this rule, for pure performance distilled is king and for looks with slightly less performance go with Mayhems if you can get it. Only reason I'm using PC Ice right now is Mayhems is insanely expensive to import to the US or it's next to impossible to get.