None of them, Beats are overpriced and are missing high ends, Bose sound good but are not nearly worth as much as they sell them for, and Skullcandy is just plain bad. Audio Technica or Grado. Much better quality.
Bottom line, stay away from Bose, Beats, and Skullcandy.
None of them. Get Audio Technica headphones, preferably ATH-M30 or ATH-M50. The only requirement is that you will need the source and amplification to be as good.You may also try Seinheisser, AKG, Beyerdynamic or Shure.