Two fine, completely different phones.
Of course, the K701-2 has a "balanced" sound that works well with various genres, though it shines with classical. With well-recorded pieces, and good stereo separation, the sound strikes a balance between clarity and, for some, lightness.
The D5000 envelopes you in velvety bass, balanced by rich mids. While I don't usually care for the bassier sound, but it has a striking effect: unlike the K701, the Denon can have exciting force. The phones, with rock, have a palpable energy - a vibration makes the phones come alive.
Me? I prefer the K701 style, and cover a variety of genres pretty well. The D5000s are great with rock or any hard-edged music, but not preferred with classical recordings. For harder sounds, the K701 will lack the power for a few recordings, but not too many. In short, it depends on the kind of music you like.