I had to vote for the thong, but the boy shorts thing is really REALLY "growing" on me... My wife doesn't own any yet but every time I see a woman on television/internet/wherever wearing those things... WOW... I wish my wife would buy a pair.
The thong is still my favorite look, and my wife owns enough of those to keep me going for a month! Maybe I will have to mix it up a bit and buy her a few pairs of boy shorts for an private christmas present...