I like the post about Triangle being a bit more sophisticated.
I had gotten into Perfume a while ago before they made the move to avex. I had the best album and their previous albums downloaded and listened to them for a short bit. I downloaded GAME and I think I listened to it very little because most of the tracks to me sounded the same and thus not much stood out. I deleted the album but after I saw the preview for Natural no Koishite I loved it and downloaded Triangle.
Triangle is my favorite!