Days of Future Past: Part 1 - S1-E11
Trivia: After Bishop travels into the past, he hears one kid telling another that they will be playing the new Punisher game "Assassin." When the Punisher was first being developed, he was originally going to be called The Assassin.
The Tale of the Dream Girl - S3-E10
Trivia: It's widely speculated that this episode inspired the movie "The Sixth Sense," although the movie's director, M. Night Shyamalan, claims that he has never watched it.