I have both the Classic and the Ipod Nano 5G. Ultimately, I prefer the nano since it is smaller, has a sleeker design and is easier to carry around or fit in the pocket. Similarly, I love the wider range of colours that are available for the nano, albeit making it hard to choose which one to get! But ultimately I settled with the purple nano.
Obviously apple products have similar designs, so like the Classic, I have found the nano easily accessible with no problems.

The sound quality again is just great. I have never had any problems, despite having to go through a few pairs of earphones of different brands, music quality seems to be great with all earphones I have tried out.

The nano however, compared with the Classic has not been as reliable for me. Firstly, I have dropped the nano a few times and had the screen freeze, along with the nano turning itself off every now and then. Because it is smaller, it is also more flimsier, and if you are as clumsy as me, it can be annoying having to worry about damaging such a delicate product.

However, apart from this, I do think the nano is a great buy, and between the Classic and the Nano I would choose the Nano since as already noted, easier to carry about, and I also think it is cuter.
I would recommend this product.