The ipod Classic has 160GB of space. That is its only advantage. It has a hard drive, so it is fragile, and the hard drive can easily be damage by vibration or shock. The Sony E465 has long battery life. Stated as 50 hours, in real life it is 40+ hours. The E465 has no card slot, so you are limited to 16GB of storage. The Clip+ has a micro SDHC card slot, so you could add a cheap 32GB microSDHC card. Battery life on the Clip+ is only around 12 hours. The Clip+ is much cheaper than the other alternatives. While the Fuze has 20 hour battery life, its proprietary connector and large proprietary cable are annoying. To get around the short battery life on the Clip+, I bought external usb battery packs to use with it. I have the both the Clip+ and Fuze. The smaller size and built in clip of the Clip+ make it much handier than the Fuze to carry around. I use the Fuze only at home.
The E465, Clip+, and Fuze have excellent sound quality. The Clip+ and Fuze are Rockboxable if you want a better equilizer and more settings.