Level E is a very funny scifi anime about aliens secretly living among us. The main character, Baka Ki El Dogra, has a name with an obvious pun (baka means fool), is the eldest prince of the planet Dogura, and is a genius that delights in tormenting people of lesser intelligence. He is a notorious prankster with an interstellar reputation.
He is on Earth because he has been assigned to annoy, er, I mean, study humans. Lucky us. There are several short story arcs in which he puts various people into hilarious situations. However, the best part of the series is the ending, which has the most unexpected twist that I have seen in a long time. Baka finally meets his match.