Right now I'm using shna's Samus Bubblebath, but your mileage will vary depending on how well your phone can reproduce the bass (unless your phone can take any section of the song, or unless you make a ringtone out of it manually). I find the snare in the less maniacal beginning to be good at catching my attention without being too distracting. And, as I said, if you're taking your own section, the first presentation of the brinstar theme on flute (least i think it's a flute) would be great.