My opinions were stated in
this recent topic regarding the iPod. I have one, I like it.
EDIT: I'm losing my mind, I think. No opinions in that topic, haha. I like mine due to its size and interface (especially the wheel, ingenious!). My third gen iPod has all touch-sensitive buttons, which are hypersensitive if you're feeling your way across the buttons in the dark, but very nice to just lightly touch when using in the car, so a mixed blessing. Showing off the lack of moving parts on it is pretty fun.

I like the design of the newest generation, if not the most aesthetically pleasing nor innovative, it is the most sensible option.
The LCD is one of the nicest in the industry, and combining with bold text interface is easy to read at any angle or in any light.
Its inability to upload MP3s from multiple computers is frustrating, I have two computers with different music libraries. Thank the RIAA for that. When docked, the computer-to-iPod interface is simple for the Mac and I heard from friends is straightforward for the PC as well using iTunes.
All said I do wish it had a few more features exploited such as built-in FM transmitter and WMA compatibility, but the size and functionality cannot be beat.