R-Type would have made a fine pack in. . . except for the fact that the game is damn near impossible on the default setting. Which isn't a horrible thing, it makes you keep coming back. . . but if I got a TG16 back in the day with R-type, I may have thrown the damn thing out the window.
I think Legendary Axe would have been a great pack in. Blazing Lazers would have been great as well.
To me, Keith Courage is average at best. It's more tedious than fun. Granted, I didn't play it until 2007.
I'm not sure what the public opinion is on World Court Tennis, but I think that's a pretty sweet game that I'm guessing, most people write off.