Ever spend five minutes yelling, "SIT! SIT! SIT!" at your DS only to have the other people on the subway get up and move away like you were a psycho? Check out this Ear Force D2 from Turtle Beach. This Nintendo DS headset includes both headphones and a mic, which means you can both hear and speak without bothering bystanders too much.
It's better than other headphones since it supports the mic, and with the mic you can talk softly while still being heard. Which is great, since playing Nintendogs on the subway really gets you that authentic fresh urine smell.