One could posit that most every genre takes some modicum of skill; rather, it would be more worthwhile to point out which games in each genre takes the most skill to excel.
RTS: Starcraft II is the first game that comes to mind. I'm not exactly the most knowledgeable about RTS games, so please forgive me if I completely forgot about some other RTS game that makes SC2 look like Playskool's "My First RTS".
Fighting: Street Fighter, again, is the first title that comes to mind. You'll notice a distinct lack of suffix; that's because there are about 13 fractillion of them.
Sports: .... Not a damn clue. The sportiest game I've played would be SSX: Tricky, a game that is FAR from easy, but I'd wager there are still harder games.
And so on. I dunno, maybe I'm just wasting my time, but I think a topic like this deserves some deeper thought.