I don't like branded glassware. I find it incredibly tacky and commercial. I have purchased many branded glasses because I like their shape, but I generally remove the brandings with acid. It bugs me to no end that many beer bars devote an enormous amount of labor and shelf space to serving beers in branded glasses.
But it's not just branded glassware. Nearly as irritating to me are those who insist that every beer must be served in a style-specific glass. The only reason pilsners are served in pilsner glasses, while pale ales are served in pint glasses—and not vice-versa—is tradition. Sure, there's an interesting history behind most beer glasses, but with regards to the beer drinking experience, there are only a few aspects of glassware that matter.
Handle: The main benefit of a handled glass is that the beer warms up slower, because the drinker is not holding the glass directly. Therefore, handled glassware is appropriate for large servings of a beer that does not taste good warm. Glass mugs also tend to be thick and sturdy, which is good if you're serving drunk people.
Glass shape: Bowl-shaped glasses (e.g., snifters, tulips, wine glasses) concentrate the beer's aroma. In general, I think beer should be served in bowl-shaped glasses, unless there's a good reason not to.
Glass size: Highly carbonated beers should be served with a good deal of headspace in the glass, so that the inevitable foam can be served, and not dumped down the drain.
Lip flare: Glasses with flared lips (e.g., tulips) make drinking highly carbonated beers easier by allowing the drinker to drink beer from under the foam.
From a functional perspective, therefore, the only types of beer glasses you need are tulips and mugs. I will, however, admit that imperial stouts look funny in a tulip, and prefer to serve them in snifters.
Any glassblowers who want to make me a tulip-stein: hit me up.