Some people obsess over temperatures and think that cooling their CPUs
a few extra degrees will improve reliability (only for excessively
overclocked systems) or longevity (not at all). People should instead
aim for adequate cooling, as opposed to cooling for the sake of
cooling, and use the cheapest chemicals that can achieve this.
Radio Shack, Loctite, Permatex, MG Chemicals, GC Electronics,
Thermalloy, Dow Chemical -- almost anything but mystery brands from
99-cent stores. Electronics supplies are sometimes cheaper than
computer stores.