Just curious. Here's what my eq looks like on the sound card (Asus xonar dgx)
And here's what it looks like in Foobar
I kinda based it off this frequency response graph I found, then continued tweaking it til I found a good balance for my tastes. I listen to mostly trance, metal, and orchestra, so I really like a crisp high and a clean mid-base line, without too much "punchy"
Well the listening experience for every person is a little different and trying to get your headphones to sound "flat" I don't really think is necessarily the best thing to do. It should really come down to want frequencies you want to emphasize or hide. I think people worry a little too much about this because probably one of the biggest components is something you have no control over and that is how the music is produced.
Most genres are more or less eq'ed in a similar fashion but you will always find stuff that falls through the cracks that has been really poorly mixed or eq'ed. Find a setting that fits well for what you listen to the most and stick with it.