Besides rotors,allignment and balancing what is causing my car to shake and shimmy at different times and at diff speeds? Sometimes it rides smoother than others but sometimes its enuff to drive you crazy!

Sometimes putting fix-a-flat into tires will cause this. CV drive axles will cause this, and worn front wheel bearings. Any loose or worn front end parts are to blame also.
I seem to have this problem on my truck. I've balanced the tires twice myself, yet still does that at diff speeds. I'm beginning to think it's the tires themselves having flat spots from sitting, then as they warm up, goes away.