Black is cool. Most of my wardrobe is black or maroon.
Poser vampire is not cool.
Goth chicks are easy and that's cool. Fat Goth chicks are easy, but no one wants to do them and it makes them mad.
Your general attitude of gloom, doom, and "I'm a creature of the night" is annoying, but this is a generalization. Some Goths whom I know are alright. Some even understand that they are not really creatures of the night. Fat Goth chicks are generally a bitchy lot who just need to get laid.
Playing in graveyards is fun.
Goths seem to be literate and well-read, as a rule, but there are exceptions to every rule. As a group, Goths tend to be more intellectual than most other non-mainstreamers.
Gothic music is...interesting. It's easier to tolerate than rap, hip-hop, and this new crap that passes for heavy metal. Usually...
German and Italian Goths are badasses who are not to be equated with Goths from any other nation. Their music is actually cool and they will hurt you. They actually live like real creatures of the night. They live and throw parties in the catacombs. They actually know something about the occult that was not fed to them by television, movies, and pop culture. They read cool books, like Clavicula Salomonis, Ars Notoria, and De Praestigiis Daemonum. Yeah, they're cool.
All-in-all, most of the Goths I know just crave attention, but act resentful when they get it. You really can't have it both ways. They're far and away easier to tolerate than "thugs" and "gangstas" or whatever. Yeah, we'll share the planet with them.