I use the EQ on XMMS, it works pretty well. For those who feel that EQ's are unnecessary for decent recordings, well that's you. Anyone who's used more than one setup knows full well that different speakers can produce different frequencies at a given power level and therefore material that sounds good on x, may sound way different on y. It's like TV sets. You go into a store and all the tv's are showing the same show but they all look different.

in itunes I use SRSWow because I like the widened sound stage it provides. On some of my systems it produces distortion. When I'm making music I prefer a flat EQ at output, but I will change the params for different instruments to get a desired sound.

overall, lets not be audio snobs. you like what you like and that's fine.