I bought a 4th generation iPod Nano as a replacement for my old, standard iPod shortly after it was released to stores. I was pleasantly surprised when I removed it from the package - the design is beautiful. It's a bit thinner than the original iPod Nano, and curves around the edges. Made completely of aluminum and glass, there are also nine color choices, as displayed on the Apple website, and all are stunning in comparison to the iPod colors Apple has produced so far. The screen is considerably large, and of great quality. No damage whatsoever has been inflicted to mine yet. This iPod also allows you to upload pictures and videos, as well as some of the games Apple offers for the iPod Touch, and so the clean images on the screen can be put to good use. It also has a few extra features which previous iPod's did not have - for instance, you can record voice memos straight on to your ipod, without even using a computer, cover flow (allows you to flip the iPod sideways and scroll through images of the albums on your iPod), genius player (pulls up a list of songs similar to the one you're listening to, so you can listen to whatever you're in the mood for), and shake shuffle - simply shake the iPod, and it shuffles to a new song! (you can turn shake shuffle on or off, so it doesn't interferre with activities such as jogging).
Although I, personally, am not very fond of the standard Apple earbuds that are included with the iPod, I was surprised for the better in that sense, too ; the music played out of the iPod with crystal clear quality. I was in literal shock at how great the sound was. Even through those standard headphones, it was magnificent.
All in all, I would say this iPod is worth the $150-$200 it is sold for (depending on whether you buy one with 8GB or 16GB of memory space). The only issue I have found with it is that the edges of the device do get easily scraped, leaving small but permanent marks on it. Nonetheless, I am very happy with my investment in this product. Worth every penny.