The best chance of big win is football... this is in my opinion. There might be other games but football seems easier to predict. I have seens several people using double digits to win 6 figures from sports betting with football only. On the other hand, I have not seen that in other events.
Sport games in my opinion actually offer the best chance to win big but I'm surprised that OP didn't include it in the options in his post. Although we know that winning big in gambling has to do with luck and of course the experience you have. Winning games is specifically attached to the game you find attractive and know how to do the best. Someone who is specialize on sport games might see it as the best game to win big while someone who is attracted to slot games might have different opinion and consider the slot game as the best to win big. I personally like sport games and see it as the best game for one to win big despite its unpredictability, I still see it as the easiest one as compared to other games. So it actually depends on your experience you have about the game you choose to play.