Even though romance is sometimes thought of as a genre, in more practical terms, romance is something that can be paired with just about any other film genre out there. Love's one of those rare universal themes, after all, and so one way to get viewers more invested in a film's characters or its story is to insert a pinch of romantic drama into genres where you might not always see a romance play out.
This goes for genres that are often thought of as being "tough" or non-sentimental, like action (which is all about physical conflict), and science-fiction (which is sometimes seen as cold or unemotional). The following films all fall within either the action or sci-fi genres (or sometimes both), yet spend a decent amount of time on the romance side of things too, ultimately showing how even action-focused or sci-fi-heavy movies can benefit from romantic subplots.
1 'Star Wars: The Empire Strikes Back' (1980)
The second Star Wars movie to be made - though it stands as Episode V nowadays, thanks to the prequel trilogy - The Empire Strikes Back is often seen as one of the best sequels in cinema history. It raises the stakes and features even better action than the first movie, and finds new, interesting things for its already well-developed and pre-established characters to do.
Part of that involves developing the relationship between Han Solo and Princess Leia, two individuals who are opposed at the movie's start, but come to develop feelings for each other as the movie goes on. It's a core romance that ends up carrying on throughout the series, and eventually has an impact on the Sequel Trilogy, given they have a child together who grows up to be Kylo Ren.
2 'The Terminator' (1984)
The Terminator wasn't James Cameron's very first feature film, but it was the one that made him a well-known name. It's a movie that expertly combines science-fiction, action, romance, and even a little horror, with it following Sarah Connor's fight for survival as she's pursued by a futuristic cyborg who wants her dead, ensuring she never gives birth to the person who's destined to save humanity from an A.I. apocalypse.
To Cameron's credit, the romance between Sarah Connor and Kyle Reese (a human sent back to protect Sarah) ends up being as memorable as all the action and cyborg-related stuff. Additionally, their falling in love is what leads to Sarah's son being born, with Kyle Reese turning out to be his father (like all time travel movies, you just have to go with it without thinking about it too hard).
3 'The Matrix' (1999)
A classic sci-fi/action movie, 1999's The Matrix started one of the most well-known action franchises of the past few decades. Like plenty of movie series, the first installment remains the best, with the original The Matrix following a seemingly normal man named Thomas Anderson who finds out he's actually destined to save humanity from being enslaved by machines.
One of his closest allies is a woman named Trinity, and the two have a romance throughout the series that begins at the end of the first movie. If anything, it feels like less of a subplot by the second film onwards, becoming increasingly important to the point where the fourth movie, 2021's The Matrix Resurrections, is debatably more of a romance/sci-fi movie than an action/sci-fi movie.
4 'Have Sword, Will Travel' (1969)
Most classic martial arts movies are pretty straightforward and primarily concerned with action over anything else, but that makes something like Have Sword, Will Travel stand out. This blends far more genres than most martial arts movies, being something of a crime/adventure/romance/action movie all at once.
The movie revolves around a large quantity of silver being transported across the countryside, with various people all competing to have it for themselves, generally through robbery. It's unapologetically melodramatic when it comes to incorporating romance elements, but it ultimately works, and feels distinct because of how many different genres it tackles.
5 'Casino Royale' (2006)
Casino Royale felt like a breath of fresh air for the James Bond series when it was released in 2006. It was a more down-and-dirty, gritty, and intense take on the character than what audiences had been used to at the time, and it seemed to treat its characters a little more like real people and less like caricatures, in comparison to some older James Bond movies.
This extended to its take on romance, with Bond and Vesper Lynd having a believable relationship develop throughout the film, aided by her not just feeling like a run-of-the-mill and regrettably disposable "Bond girl." The relationship's tragic end also seems to affect Bond in subsequent movies, proving to be a significant part of the overall five-film-long saga now definable as the Daniel Craig era of James Bond.
6 'The Mummy' (1999)
Primarily, The Mummy is an old-fashioned action/adventure film with strong fantasy elements, and a little romance sprinkled on top for good measure. It tells a supernatural story set decades ago in an exotic locale, and with a hunt for treasure driving the narrative... so it's kind of just Indiana Jones, except Brendan Fraser is in the lead role; not Harrison Ford.
But it did a good job when it came to casting, because Fraser and Rachel Weisz are both likable in the lead roles, and both have good chemistry when their two characters ultimately fall for each other. The Mummy is a pretty straightforward film overall, but its action, adventure, and romance elements largely work, ensuring it's a satisfying popcorn movie.
7 'Crouching Tiger, Hidden Dragon' (2000)
Crouching Tiger, Hidden Dragon was a surprise international hit when it was released in the early 2000s, with its blend of action, melodrama, and romance proving impossible to resist on a worldwide scale. It's a film that revolves around a prized weapon that various people are trying to get, which leads to plenty of intrigue, character drama, and fight scenes.
It's a beautiful-looking film, and its unique, somewhat fantastical action scenes still stand out over 20 years on from the movie's release. As a tragic romance, it works too, with the emotional core from this emphasis on relationships within the film helping it be even more resonant as a drama, and not solely a martial arts movie.
8 'Avatar' (2009)
25 years after The Terminator, James Cameron once again blended sci-fi, action, and romance expertly with 2009's Avatar. In 1997, he also combined spectacle and a dramatic love story with the disaster movie Titanic, though the romance is front and center there, to the point where it wouldn't be accurate to describe it in any way as a subplot.
But with Avatar, the focus is initially on the uniquely alien world and the excitement and action that comes from the characters spending time in it, with a romance between the two main characters - Jake Sully and Neytiri - slowly building throughout. It's exciting, romantic, and touching overall, with the mix of genres and tones ensuring Avatar stands as one of the best sci-fi movies of the 2000s.
9 'Guardians of the Galaxy Vol. 2' (2017)
Guardians of the Galaxy Vol. 2 takes a page out of The Empire Strikes Back book by crafting a sequel that gets more personal with its characters, fleshing them out to a greater extent. It's a movie that allows all the heroes a chance to get introspective, and centers around Peter Quill/Starlord reuniting with his mysterious father while also developing deeper feelings for Gamora.
The romance between the two never becomes a focus, but it is an important part of the film, and also paves the way for one of the most devastating scenes from Avengers: Infinity War (released one year after Guardians of the Galaxy Vol. 2). The Guardians series has always been beloved for its engaging characters and their interactions, with the bond between Starlord and Gamora a big part of that.
10 'Top Gun: Maverick' (2022)
Even though Top Gun: Maverick only had one big action scene, it was admittedly a spectacular (and very long) one. The movie revolves around the aging pilot Maverick being enlisted to train young recruits to pull off a dangerous mission, with much of the film depicting the recruits training, and then the final act showing the mission itself.
Before the action-packed climax, Top Gun: Maverick also finds time for a romantic subplot between Maverick (Tom Cruise) and Penny Benjamin (Jennifer Connelly). It's a little weird how Maverick's love interest from the first (played by Kelly McGillis) isn't even mentioned, even though various other characters return or at least get referenced in dialogue, but at least the chemistry between Cruise and Connelly is solid.