Bit Tech just published a Watercooling Fluid Shootout, which compares three of the leading non-conductive fluids to good old distilled water.
"But all of this was for one worthy goal – is there a fluid that reigns supreme? Does anything do water's job better than water? The numbers don't lie – nothing is better than pure, straight up water so far, at least where temperatures are concerned.
But there are a couple fluids that perform just as well, and their side benefits of colouring, anti-corrosion and (most of all) non-conductivity make them well worth your time. Though temperatures are our primary concern, I've also made sure to note other aspects of each fluid that can have an effect on overall usability – colouring, bubble dispersion, and clean-up. So which ones are truly better than water, when you take all of this into account?"