Street Fighter 4 has sprites? Anyway I don't feel strongly about SF2 or 4. It seems crazy to me that Third Strike isn't the most popular game in the series.
Mario 3 > World maybe, but they're pretty close. I agree about the general feeling of happiness from World, that isn't present in 3 as much. 3 has better level design and difficulty curve, and World has the dumb cape. That's what separates them in my mind, they're both really quite good.
With Super Mario Kart, I've never succeeded in getting anyone into it unless they played it when they were younger. My group of friends hovers around Mario Kart 64 or Crash Team Racing, those seem to be the ideal point between skill and fun or whatever. The SMK controls can be tough to someone who's used to the newer ones.
I've been meaning to play Super Meat Boy, should probably do that soon. Sounds like something I'd like.