A ranked game I played the other week, our gragas and caitlyn were feeding, around 30 min the enemy pushed our mid inhib, enemy went to baron which I'd luckily warded just before they went for it, we ganked them and won.
I mean it's not like game changing baron ganks are unheard of, but they were so far ahead of us (it was like 15-35, we took 3 outer towers and they took all our towers except the ones defending top and bottom inhibitors) makes it a pretty big comeback.
Also one of the times I was playing AP shaco, we were slowly slipping behind, losing most teamfights, eventually they locked us down in our base, I went and backdoored their bottom lane in just a few seconds using a combination of jitbs (they did like 200+dps to towers each at this point), lich bane (i had around 800 ap) and my ult clone. In around 90 seconds i pushed two towers, their inhib and one nexus tower. AP Shaco is seriously underrated.