French, though I've lost quite a bit (happens when you don't speak it for six years).
There was a guy I met while in France who was from Norway, and his father was a diplomat. He spoke his native language obviously, English, German, French, and Arabic. Here's the kicker though: He had a perfect native accent in each of them (and learned them in about a year or so). When I first met him, I thought he was from California. I was floored -- probably the most gifted language learner I've ever met.