As versatile as Charlize Theron is, we’d never quite seen her in a true romantic comedy until Long Shot. And we can’t say we expected her first one to be opposite someone from movies like Pineapple Express or Neighbors. But Seth Rogen, attached to the rom-com for some time before it was made, knew he wanted to work with Theron. In an interview with ET, he joked that he only had to wait seven years to become successful enough to do so.

Even though beloved comedian Steve Carell had been building a resume of more dramatic roles for years (which included Little Miss Sunshine, Dan in Real Life, and even Crazy, Stupid, Love), his performance as convicted murderer and wrestling enthusiast John du Pont in Foxcatcher still felt unpredictable. Unrecognizable as well, thanks to the Oscar-nominated makeup and prosthetics. That Carell paired up onscreen with heartthrob Channing Tatum (who had previously kept to action or romance roles) made Foxcatcher one of the most surprisingly cast movies in recent memory.

If someone told us 20 years ago that Elaine Benes and Tony Soprano would someday appear together in an independent romantic comedy, we’d have never believed you. But that’s exactly what happened when Louis-Dreyfus put a pause on her riotous comedy roles and James Gandolfini hung up the mobster hat. The two have delightful, sincere chemistry in Enough Said, but because Gandolfini died unexpectedly of a heart attack before the film’s release, it turned out to be among his greatest and final performances.

Oscar-nominated director Sofia Coppola had Bill Murray in mind from the minute she began writing this atypical romantic comedy. Specifically, she imagined the role of Bob Harris as the perfect chance to show off the SNL alum’s “more sensitive side.” And she also found the idea of Murray in a kimono endlessly amusing (the visual would become the movie’s poster). In the film, Bob makes an unusual connection with Charlotte, a recent college graduate. The actress who ended up playing her was a young Scarlett Johannson, who was essentially unknown at the time yet still found herself standing toe-to-toe with the seasoned comedy actor.

Ace Ventura, the eccentric pet detective, and Rose DeWitt Bukater, the first-class passenger aboard the Titanic … This bizarre combination of star personas in Eternal Sunshine of the Spotless Mind is not lost on star Kate Winslet herself, who cited the “totally new and challenging” pairing as a key incentive to join the project. Also cast against type was Jim Carrey, who had already started his genre diversification a few years back, with The Truman Show.

Lady Gaga surprised us in A Star Is Born not with her talent (we already knew all about that from her Sound of Music medley performance at the 87th Oscars) but rather with her vulnerability, in a stripped-down, personal role quite different from how we’d seen her on American Horror Story or in music videos like “Bad Romance.” But beyond this departure from avant-garde pop performer, the story of how she ended up in a perfect onscreen pair with Bradley Cooper is also special because it almost involved so many others. At various moments since the late 1990s, actors like Will Smith, Paul Walker, Tom Cruise, and Christian Bale have been in talks for the role that eventually went to Cooper. And in another universe, Aaliyah, Alicia Keys, Lauryn Hill, Shakira, and even Beyoncé might have been the ones icing their knuckles with frozen peas in a parking lot, not Gaga. While some of those alternate combinations are tempting to imagine, we’re still off the deep end for the dynamic duo that ended up dueting in the Oscar-winning original song “Shallow.”