MEElectronics HT-21 Travel (Black)

Pros: They fit into my hoodie pocket! Lightweight. Not bulky. Fold-flat design. Inexpensive but sturdy construction nonetheless. Sound GREAT.

Cons: Cannot think of any.

Summary: These tiny little headphones pack a wallop in terms of their sound quality and ability to isolate your ears from the outside world. They're really very simple, the design is a stroke of genius, and you only have to spend what amounts to pocket money to have them. I love these headphones. This may be in the running for the best $20 I ever spent. Don't be turned off by the low price point, these are great.