A bit more complicated
First of all : Quake (as much as I like it) and Command & Conquer aren't really appropiate, as you can still buy both series. Would mean everybody would have to buy the games, since I can't provide them. Other than that Quake is a bit hard to measure anyway. No discussion, they are no-go's
Second thing : You need to choose two games from that particular series. So, which two from SMB, TMNT and Castlevania (bear in mind that we already have played 2 Castlevania games in the league
).