A few more options:
ATH M50 for more bass
Shure SRH 440 if you want really nice imaging, good soundstage for a closed portable, and dont mind a little light on bass.
To summarize:
SRH 440
Sound signature: Neutral, forward mids, a little light on bass, great imaging and depth
Isolation: 6/10
Comfort: 8/10
Portability: 7/10
Strengths: imaging, neutrality
Biggest weakness: isolation, bass
HD280
Sound signature: Very neutral, slightest hint of warmth, average soundstage (a little better than the V6)
Isolation: 8/10
Comfort: 7/10 (nice pads but serious clamping force when new)
Portability: 6/10
Strengthss: Neutrality, naturalness, isolation, durability
Biggest weakness: Looks pretty stupid, slightly veiled upper midrange on some tracks can make it a little boring
ATH M50
Sound signature: V-shaped (emphasized bass and treble), recessed mids, small soundstage
Isolation: 8/10
Comfort: 6/10
Portability: 6.5/10
Strengths: bass, isolation, durability; new version has replaceable cable
Weaknesses: recessed mids, small soundstage
V6
Sound signature: neutral, slightly bright, average soundstage, a hair light on bass
Isolation: 6/10
Comfort: 8/10
Portability: 7/10
Strengths: Neutrality, comfort, industry standard monitoring and mixing headphone
Weaknesses: Boring, flat sound, not very dynamic
UE6000
Sound signature: moderately colored, slightly v-shaped, above average soundstage
Isolation: 6/10
Comfort: 9/10
Portability: 8/10
Strengths: Fun, balanced, good soundstage, replaceable cable, in-line mic
Weaknesses: Not very neutral tonality, mediocre build quality - not professional headphones
If you're buying a gift for someone who likes mostly pop music, I would look at the UE6000 and ATH M50, or SRH 440 if they don't like a lot of bass.