* Bad breath
* Discoloured/rotten teeth
* Smokers
* B.O
* Druggies
* People who go on about how wonderful they are
* People who go on about how band/music style X (usually something very obscure) is the best thing since sliced bread and how band/music style Y (that maybe I like) he wouldn't be seen dead listening to because it is supposedly so uncool.
* Overweight