Around here, sky's the limit. You can make cabinets as focused or as broad as you would like. We will love to see what you come up with.
My only caveat, when basing a cabinet on console games, is that most console games are based on long sittings. You do a mega man cab, it takes away from the sit and quick play kind of feel. You might want to think about adding save state and load state buttons, that way you don't have to start from the beginning every time you sit down and play. Press one button and you are right where you left off.
What you can do, if the controls are not overly specialized is make a machine that is "stealthly universal." Lets say you make a dedicated Kirby cab, you could make a machine kirby themed that starts up into Kirby on startup, but you could make it go into an menu of additional games when a special combination of buttons is pressed. Whether you want everything available, or just 10-50 favorite games you would like to have on your machine.