Wines that are overpriced because they are popular or have a well-known name. Oh, and corks that break. I'm a big fan of screw tops and those cool German glass stoppers.
The person who wants to discuss in-depth the characteristics and personality of the wine, how it dances across their tongue, reminding them of a funny thing that happened on the way to Napa. We all know "that guy." Don't be him.