I'm currently a bit fascinated with different ways of representing my listening history.
I really like
LastGraph which was inspired by
Lee Byron. The graphs show how my listening preferences (and in particular how often I listen to my favorite artists) change over time.
I also like
these visualizations by Martin. They show how artists move up or down over time in my chart.
Recently I tried to visualize my top artist chart using artist images, and readjusting their sizes so they correspond to how often I've listened to each artist respectively. Here's what I've been listening to since my last blogpost at ISMIR 2008:

I think this montage says it all: I like black and white music from solo artists playing guitars.