What would be the best iPod for my desires?

I've been considering buying an old iPod for a long time, but I'm not sure which one to go for.

I'm looking for something that will let me listen to my massive collection of music, podcasts, and radio shows (all MP3 files) without connecting to the internet. I want a nice interface, for album art, ease of selection, and all that stuff.

I'd also be very tempted by an iPod Touch if I knew they could reliably run Spotify, but that sounds a bit unlikely based on what I've read so far.

Indulge me in your wisdom!