i play overwatch the same way i play league, i just play whoever's fun
i like champions that have varied ways of using their abilities, so mobility and "skillshots" are usually my thing. zenyatta has neither of those, you just click on bad dude and shoot, or click on good dude and don't look back. his ult is really interesting but the base experience of playing him is really monotone for me
all my most played champions (tracer, d.va, reinhardt, symmetra, pharah, roadhog) have abilities like that
also they have to have fun personalities and visual designs and reaper feels kind of a joke character because of how ridiculously edgy he is.