Poker and Blackjack is the only games i know that requires skills, the rest is you need huge bankroll in order to yield some profit. Because slots and dice are all based in chance and probability. You may encounter lose streak especially when you increment your based odds per bet.
Sports betting can be also considered especially when it requires knowledge and research.
I think betting on sports can be counted as skill based gambling, because you need to know many things in order to be
profitable in long-term. In my opinion betting on sports require more skills than playing Black Jack, but it's just my opinion.
For every game you need some skills, and I think skilled people have more chances to win when they play. Who plays
without any knowledge about the game he will lose all!