Which Portable media player should I get? (Mp4, Mp3, etc.)?

Have you thought about a Zune? It's not that much more expensive than these other products you are considering. It does MP4 and WMV video playback, MP3 and WMA Sound, FM tuner, WI-Fi, it can store pictures and has a built-in 30GB Hard Drive! Microsoft has excellent support system for it with a no-hles warranty policy and it can also play back video on your TV just like the Cowon D2. With these other devices, you are limited to the size of the SD Card you are using, 2 Gigs SD Card only holds about 400 CD quality songs. In addition to it, the NV3 is a camera with audio playback capability, which means it will drain the battery very quickly. My friend has a Cowon and he says it is also a battery hog, however, he does like it a lot. If you are very insistent on only these three models, I would go with the Cowon D2, however, you should strongly consider the Zune. It does everything you want and is more likely to be the standard in portable media player within the next 3 years.