Well that's kinda funny, I get asked it a lot. These days when I'm not producing I don't listen to music at all. Because I'm constantly 'musicing' for production and gigs I find that in my free time no music at all is the best way to get re-inspired and come up with new ideas. In saying that I do get to listen to a lot of stuff that isn't my own, it's usually what other people are listening to that I'm around or just stuff that's playing where I go. Which is cool too cos I get to see what other people like and then try to understand why they do.
Back in the day before I was producing, I didn't really start listening to music til after highschool. I went through a few little phases of random genres that would only last for a couple of weeks but ended up on dance music by the time I was about 17. Producing by 18. I listened to euro pop and hard dance that were popular at the time but loved happy hardcore the most when i could find it (it was hard to find back then when the internet was still a baby =P).