I agree, it's a shame I've had great fun using the Parametric EQ in Neutron Audio, I'd love to see them work a Desktop verision of their software with windows compatability, otherwise I'm lucky enough to have a copy of jRiver. Though frankly I never use it, FooBar has some Parametric EQ Plugins however
Foobar also has a spectrum analyzer that can show you the frequency response of each song and you can calibrate your headphones for a flat signature once you know exactly how much things are boosted/recessed.
If you turn your volume to 0, you will get a perfectly flat response