Asking this question because I was curious about how any of you would answer it. For me, I would be a Electric-type gym leader because I had a lot of fun with training Electric-type Pokemon in the games. As a stroke of luck, I was also admitted as such a gym leader in my college's Pokemon League (Just to clarify, A lot of people there still play those games back there. ;p ).
*Edit: I always seem to call them "Thunder"-types. Sorry about that.*