As goofy as the Bumbling Dad persona is, it is actually quite clever how he used Raven's friends to try to convince her daughter to be a Demon Spawn. It just goes to show why Trigon is considered the source of all evil. Fortunately Raven isn't stupid.
Beast Boy tricking everyone in the end. Taking out the context of them all dying and becoming ghosts, it's pretty awesome to trick the pranksters by going along with their prank only to then turn it on themselves.
The Titans have an incredible battle using a Humongous Mecha against Gizmo's giant robot army.
Not to mention Robin beating Gizmo with just a the left leg, with his upgrades to match.
Starfire turns out to be a surprisingly effective villain in "Starfire the Terrible". She blows up the moon and while her evil lair is made of cardboard, it has real lasers and a robot army that gives the Titans a hard time.
Robin and Cyborg accidentally combine their attacks to create an explosion so powerful, it can be seen from space.
Once Raven realizes how awesome her legs are, she gives them quite the workout. Just ask Jump City's villains.