Sennheiser's CX 500s are one of our favourite new pairs to recommend to anyone as a first upgrade from the bundled 'phones that came with your MP3 player. They're a great choice for joggers or gymaholics, as the in-line remote offers quick access to volume controls. They're extremely lightweight and unintrusive, too, so they stay in place well when you're active.
V-moda's Vibe earphones are heaviest on the bass, making them a good choice for devoted dance and rap fans, but less recommended for singer/songwriter connoisseurs. We were impressed by their performance, and their reduction in price from their original near-£75 price tag makes them a good choice for the style-conscious, as they come in many colours.
The Ultimate Ears Super.fi 3 earphones are a good choice for anyone looking for an extremely balanced sound, as there's no real favour given to any one frequency. These compare well to the Shure E2c earphones, but arguably offer better overall clarity. There's much less bass here than the aforementioned Sennheiser and V-moda offerings -- instead, they offer studio monitor-esque performance.
Finally, a pair of Zen Aurvanas are still a good choice if you want a lightweight fit and good overall sound quality. If you can't afford Shure's SE310s, these are a fine alternative, with excellent clarity in the high end. They're much lower profile than the UEs or V-modas, making them another good choice if you want an unintrusive fit and don't want the in-line remote fixed to the Sennheiser CX 500s.