I never leave the house without my iPod. Anywhere I go, for any length of time, I have it on me. So, naturally, I prefer to have the best sound quality possible, and, usually, standard Apple headphones do not offer that. My personal favorite of companies which produce high quality headphones is, without a doubt, Skullcandy.
I recently bought Skullcandy Titan earbuds, and, and, yet again, felt great about the investment. These headphones comfortably fit into the listeners ears, and have great sound quality. Listening to music through these earbuds is literally the closest I have ever come to feeling like I am in a room where nothing other than the music on my iPod playing, even if I am on a plane or in a crowded store.
Although they are a little pricey, I would say that these headphones are worth the investments. I am yet to be disappointed by them. They truly bring the advantages of portable music players to their highest abilities.