HardwareSecrets added five new thermal compounds to their previous roundup, for a total of 30 different thermal compounds from major brands. They also tried another "alternative" compound: spray oil. You can check out the results over here.
Here is a snippet:
"Following up on our Thermal Compound Roundup - July 2011 review, we are adding five more thermal compounds to our roundup, for a total of 35 different models from Antec, Arctic Cooling, Arctic Silver, Biostar, Cooler Master, Coolink, Deepcool, Dow Corning, Evercool, Gelid, Nexus, Noctua, Prolimatech, Scythe, Shi-Etsu, Spire, Rosewill, Thermalright, Thermaltake, TIM Consultants, Titan, Tuniq, Xigmatek, and Zalman. In this review, we will determine if certain products are superior to others. We will also try another "alternative" thermal compound to see if it works."