If I had to pick? Probably Starcraft II, it requires much more focus than a shooting game, and the quick thinking / thinking outside of the box takes some brain power imo (why else have people not been able to do this?). Considering I'm in Silver (as I failed all my placement matches) I feel I excel at other people my league in terms of macro.
Micro? Erm. I'm Zerg, so that's only when I muta harass or do micro with Burrow / Banelings XD