The Sarcasm Z80 Assembler is the sweetest assembler in existance, for every CPU, even those which it doesn't support (which is almost all of them).
I once created some music. Ninety Seconds is better than anything you've written, and Life with Television... Well, it could be worse. I kind of like it. If only there weren't better music to listen to.
I also wrote a little something to demodulate Caller ID signals which, surprisingly, is a problem that doesn't seem to have a well-documented solution. It makes me rather happy that I was able to come up with one.
...and just in case you really have nothing better to do, there's whatever this is an excuse for. It may be an excuse for a blog, but I'm not really sure.