fr0stdude :
I was thinking of using them for a bit of gaming and a bit of Music. I would go for the HD59s or 60s if I had the dough xD
Both the KRKs and ATs you linked to are closed phones, not like the usual Senns. They are fine for music and games. They MIGHT require a dedicated headphone amplifier or a good sound card with a headphone amplifier, because they are meant to mate with pro-audio equipment that has this dedicated headphone amplifier to drive them (they are not terrifically power efficient).
The closed aspect of these phones don't leak sound, but again, you can't hear someone else either, if you game with others wearing headphones.
I would recommend any of the real headphones over those crappy Steelseries, or other...