If your headphone use is primarily mobile, you need to check out the DT1350 from Beyerdynamic. I know I tend to rave about Grado Labs headphones, but their open design means they're not particularly useful on public transit, in an office, or any other place where sound should not leak in our out.
The problem is, most headphones targeted at portable use are not very good (yes, I'm looking at you, Beats). But that's what I love so much about these Beyerdynamics: In spite of their smaller profile and excellent noise rejection, they sound fantastic. In fact, if I can't find a pair of Grados around the house when I'm watching a movie late at night, I'll reach immediately for our DT1350s. Clear and neutral mids and highs are balanced with full lows, resonant without being boomy or thumpy.
Combine this amazing tone with rock-solid German construction and a snappy carrying case, and you have what is undoubtedly the best set of portable headphones I've ever tried. I recommend them without reservation.