The first thing I did after Legacy came out was put together a Defense of the Heart deck. It's casual credentials are up to snuff, good nomination. Rancor may be too good and too specific, but I think it makes all sorts of green beatdown decks a lot better, and green beatdown decks are almost always casual because they can't actually win tournaments. I'm going to delay on my nomination for the moment, but I will say that Legacy was a very good set, lots of good commons and uncommons, and very few useless rares.