Any songs against a dichotomous perspective of sex/gender?

[Human Lefts]

Basically, anything that the main theme is that we're not male and female.

[Robespierres Neck]

I could be off by suggesting this, but Sonic Youth's 'Androgynous Mind' is what came to mind:
http://www.youtube.com/watch?v=tQ63sYdWKmg

[Yuppie Grinder]

You need to listen to the band God is my Co-Pilot.
You would probably enjoy queercore in general. I recommend Team Dresch.

[Regicollis]

Lola by The Kinks

[Yuppie Grinder]

Lola by The Kinks

The Raincoats version even more so. Their version is one of my favorite guitar pop tunes ever and messes with gender roles not because of a specific political agenda but because it feels free and fun to fuck with gender.

[PetyaRostov]

Androgynous - The Replacements
btw God is my Co-Pilot and the Raincoats are rad.

[Камо́ Зэд]

Perhaps The Bad Touch by Bloodhound Gang might count?

You and me, baby, ain't nothin' but mammals . . .