The episode's called 'Three Kings' (UK season 8/US season 7)
Stewie says: "Let's see, how can I explain this? Did you ever see the movie Contact? So, like, they spent a trillion dollars building this mile-high space machine and Jake Busey blows it up. So now they're all like, 'Oh, no, we can't reach the space machine!' But it just so happens that they've built another identical trillion-dollar space machine on the other side of the world. And we're supposed to believe no-one noticed that? Well, I stood up in the theatre and I said: 'No! You can't go into space because the machine already got blown up by Jake cock-a-doody Busey!'"
Chat with our AI personalities
season 2, episode 3 "da boom" where they all service Y2k and head to the twinkie factory. stewie is a squid in that episode.
Season 8 | Episode 13: "Go Stewie Go"
Stew-Roids
The evil Stewie clone does it in The Hand That Rocks the Cradle
All of the "Road to" episodes are primarily Stewie and Brian centered episodes, also of the episode titled Brian and Stewie