Aniston's Road-Trip Must-Have: Justin Theroux!

Spoken like a true woman in love, Jennifer Aniston revealed to ET that she only needs one person to take with her on a We're the Millers style road trip -- her fiancé Justin Theroux!

"I would bring my only nearest and dearest friend, Justin," she replied when asked which of her famous friends she would bring with her on a road trip at the We're the Millers premiere in New York City Thursday night.

Pics: Jennifer Aniston and Justin Theroux's Night Out

But Aniston was a little more practical and down-to-earth when revealing her road-trip essentials.

"Water, food, good music, and uh ... toilet paper," she smiled.

Aniston stars opposite Jason Sudeikis in her latest film, in which she plays a stripper recruited by Sudeikis to act as a fake family (along with their "kids" Emma Roberts and Will Poulter) in order to get through customs to pick up marijuana from Mexico.

And who is Sudeikis' drug-dealing character David picking up marijuana for?

None other than The Hangover star Ed Helms!

Video: 'We're the Millers' Speed Round -- Travel Edition!

"Oh my God, I am not the go-to actor for drug kingpins in general, but, I'm really glad they came to me with this one because it's just something I would never get to do otherwise," he told ET. "It's totally ridiculous and silly, and a hell of a lot of fun."

And who would he rather go on a road trip with, Aniston or Sudeikis?

"Jennifer, right?," he laughed. "Why? I don't know, she's prettier than Jason."

Check out the video to hear Sudeikis explain Aniston's head-turning stripping scene audiences already got a peek of in the film's hilarious trailer, and what scene-stealer Poulter thinks about a possible sequel!

We're the Millers hits theaters Wednesday, August 7.