which commercial beers are you talking about.
Rules of thumb that I follow (might not be universal):
lagers served colder than ales
the more carbonation the lower the temperature
higher the fg warmer the temperature
the more body in a beer the warmer the temperature
don't frost your mugs unless you don't want to taste what you are drinking.
traditionally beer isn't served cold. The colder it gets the less flavor you taste. Some beers are meant to be served very cold, but generally the whole "ice cold beer" motto seems to come from BMC type beers, to help with the "drinkability".
I love the coors light mountains that tell you when your beer is cold enough to drink. Always gotten a kick out of them