Arctic Silver 5 is extremely high quality but unless you're overclocking like mad it's little more than a flashy investment. CoolerMaster ships their heatsinks with some halfway decent thermal compound. If you don't mind spending an extra 7-10 bucks, go for it.
However, Arctic Silver 5 is a capacitive compound and should only be used on CPUs with a large surface area and no exposed contacts. For GPUs, RAM, Chipsets, etc... use a ceramic compound such as Arctic Silver Ceramique 2