The Simpsons - Featured in these episodes:

• Season 1, Episode 8 - The Grasshopper Experiment

  After Howard affected an Indian accent to phone Lalita Gupta on Raj's behalf, Howard told Raj he could now thank him. Raj asked, "For what, making me sound like a Simpsons character?"

• Season 2, Episode 4 - The Griffin Equivalency

  After Penny was the only one of the group to attend Raj's People magazine reception, Howard asked if Leonard was going to mope around while Penny was out with "Doctor Apu from the Kwik-e-Mart".

  "Howard: So you're just going to sit around here and mope while Penny is out with Doctor Apu from the Kwik-e-Mart?
  Leonard: It's not a date, and that's racist.
  Howard: It can't be racist, he's a beloved character on the Simpsons."

• Season 8, Episode 12 - The Space Probe Disintegration

  When Raj asks Howard if everything he knows about Hinduism comes from Indiana Jones, Howard replies "No, there's also Apu from The Simpsons."

• Season 9, Episode 3 - The Bachelor Party Corrosion

  When the guys get a flat tire in Mexico, Sheldon worries, "What if it's banditos shooting at us? What if we get kidnapped? What if we end up in a factory making Bart Simpson piñatas for the rest of our lives?

• Season 9, Episode 21 - The Viewing Party Combustion

  Sheldon says that Leonard's refusal to attend the mandatory quarterly roommate agreement meeting is a consequence of a generation raised on The Simpsons.

  "Sheldon: See, Leonard refused to participate in a mandatory quarterly roommate agreement meeting. This is what a generation raised on Bart Simpson looks like.
  Leonard: You love The Simpsons.
  Sheldon: I love Lisa Simpson."

• Season 10, Episode 9 - The Geology Elevation

  When Professor Stephen Hawking called Sheldon to help him deal with his feelings of professional jealous, Hawking mentioned how he had never won a Nobel prize but was okay with it because he'd been on The Simpsons.

  "Hawking: I understand you're struggling with professional jealousy.
  Sheldon: Thanks, Leonard, now he's not gonna think I'm cool.
  Hawking: Don't worry, I know how you feel. I have never won a Nobel Prize.
  Penny: Oh, wow, that doesn't seem fair.
  Hawking: It's fine. I've been on The Simpsons."