ive dwelled into quite a few scales, but aside from the ones already posed, i would check out an exotic scale called the double harmonic minor. its basically the harmonic minor position 1 and 5 put together to create an "ultimate" harmonic minor. haha. another cool sounding scale is an exotic scale called "promethius". keep in mind that these exotic scales all have roots to either the major and minor scales. its very evident to tell that the harmonic minor scale is jsut a spin off of a plain old minor scale with a few eastern sounding tones added. same thing with all the scales you will learn; the roots are right in front of you with the scales that you hear everywhere. major and minor pentatonic, lydian and ionian, aeolian, bla bla bla, theyre just fancy names for scales you aughtta know if you want to shred.