Hi guys. Sorry if this question has been covered in detail in another post. My question is what are the major differences with the bulbs that use the different gas types such as Argon, Krypton, Xenon, & Halogen? The thinks that I'm interested in learning is which is the brightest, which is the purest white, which are the most efficient and which last the longest before burning out. Does anyone know of a web page that goes into details on this issue? Thanks in advance for any and all info.