Lucio is my go to support for pushing the payload or holding points. You just stand there with a reindhart healing while firing off your sound gun (which actually does tons of damage) then you can boost the heal when its off cooldown or ulti when shit gets real

its pretty hard for the enemy to shut you down if the lucio lives. (seems pretty sweet with a soldier 76 near you too to throw down the extra heal.
and ofc blowing people off the edge of the map or down a pit is also fun ^^
I also love setting up a kill room with a symmetra on my team, Turrets all around (make sure the room is on the main route they have to take) then hook them into the room as roadhog, its brutal