I try not to come across as a beer snob. If I'm ever accused of being a beer snob, I just tell them that I prefer flavor.
I guess I'm fortunate enough that most of my friends enjoy what I consider to be good craft beer. But I typically only bring stuff that is easily available, nothing rare or aged, unless the others reciprocate. I've turned a few friends on to better beer over the years, and that has benefited me in the long run.
I cellar, and my wife knows to not take anything out of the cellar, or let anyone else take anything out of the cellar. When I have people coming over, its best if I have some homebrew, but if I'm out, I'll make sure to have decent craft beer on hand.