The Apple iPod touch - it's the device that can do just about everything an iPhone can, bar making calls. It's a seriously-capable device, and probably the most versatile of all MP3 players - as long as you're not talking about the simple playing of music. On that front, you're limited to a small range of codecs and are tied to iTunes. But if you can stomach those deficiencies, it's simply brilliant.
Read the full iPod touch 4th Gen (2010) review