I voted AFM, BSD, and Mettalica. I don't really see any reason to have AFM, MM, or MB in a collection that already has one of those games with how similar they are to each other, especially when you're limited with how many games you can have. From your description I picked AFM since it seems you like that the most, but keeping any one of those would be great. I picked BSD because something older and a bit simpler will add some more variety to the collection (Plus it's just a great game!). I picked Metallica mainly because it's a game I'm familiar with that I know is really good, but ACDC would be good too of course, or Batman. Ultimately the decision is up to you. I'd definitely finish fixing up BSD and getting some time to play before deciding whether or not you want to keep it though.