Punching out Juggernaut. After beating him up with your powers, you finish him off with three simple punches. Depending on who you are, it can become hilariously more awesome.
Cyclops taking out the tower and a sentinel, via a Fastball Special. Yep, Cyclops gets tossed into the air, blasts up a sentinel to shut it down, then runs up its body and shoots out the radio tower beaming Bastion's sentience around.