I got 4 pairs of these for my XL. They are kid sized so the ankle-biters are more comfortable, PLUS they have an input for wired devices like iPads, Nintendo DS, etc.
http://amzn.to/1eEAU5U
They show as out of stock right now, but I got them less than a month ago.
As far as buying the OEM ones, with my Honda Odyssey, the OEM headphones were very nice, but cost $160 through the dealer. No way I'm handing a set of headphones to my kids that cost that much. The OEM ones from GM feel ***** to me. They look very much like the Audiovox headphones that you can get from Amazon for $24.
I just get the cheapest headsets I can from Amazon and if the kids break them, my feelings don't get hurt so badly.