Hi Ardilla,

Welcome to the forums!  I'm surprised no one jumped on this post, as you might have guessed, everyone is passionate about which non-planar phones are "the best" and are usually anxious to put their 2 cents in.

The most popular from the feedback I've gotten over the past few years is the HD800's.  Of course you're right, the Grado's being a lower impedance dynamic headphone are a sure shot with this too.

The best place to find discussion about how different headphones sound on it would be on headfi.org

There are some very long threads over there on just that subject if I remember right.

Again, sorry for letting your question go un-noticed for so long!

Thanks,

Steve