Lately I've been experimenting with the ESX24 Sampler, a software instrument in Logic. It has lots of really awesome built in patches, but why limit yourself?
I built this one minute loop around the patch I made for the wobbling bass. I kept it simple and tossed in a drum kit and distorted guitar using a simple AB pattern with an 8 bar intro of just the bass and drums. It's a little bit more "electronic" sounding than most of my stuff, but it's fun to experiment. It's one minute long and infinitely loops for a fade out.