"I'll have a beer."

A man or woman walks into a bar.  They walk up the bartender and say "I'll have a beer."  The bartender nods and pours them a random beer and sets it down in front of them.  This has to be one of my biggest pet peeves in entertainment.  I don't care where you go, if you walk up to a bartender in real life and say "I'll have a beer," they are going to look at you dumbfounded and ask "What kind of beer?"  Now I understand that there are reasons why television shows and movies can't/don't use brand names such as Miller Lite or Blue Moon.  But ordering "a beer" isn't quite the same as saying you'll have a gin and tonic.  If you walk up to a bartender and order a gin and tonic, they will simply pour their rail gin.  For the love of God Hollywood, can you please have the common sense to understand that a beer isn't just a beer.  It's not just a standard drink that people order.  Unless the bartender is Miss Cleo, they aren't going to know what kind of beer you want.  Especially in this day and age when microbreweries are popping up everywhere.  There are different styles that can easily be replaced in the phrase "I'll have a beer."  For instance, "I'll have a pilsner." or "I'll have a stout."  How has this gone unnoticed and uncorrected for so long.  So this is my plea to all writers out there, the next time you write in a scene at a bar into one of your shows or movies, please take the time to think about this.