I think that sports betting gives you the most odds to win because if you know the teams and how they play and what quality are they, you van easily win. It is also the easiest kind of gambling to find a loophole in, if you know someone that knows the results ahead on the rigged game. Other games such as dice or other depend on a random generator and does not offer you much odds on winnings.
Blackjack is probably on number 2 because you need to know to play and you control part of the game. You could also count cards if you know how to.
I agree with you. Sports betting is the best play you can try. Its easy to predict other than any games. All you have to do is check players or teams background so you have a knowledge which team is worth betting for. But there are no guarantee you can always win. This is still gambling. Win or go home.