Action + Thriller + Martial Arts + Drama + Monster + Historical + Romance = Brotherhood of the Wolf.
Romance-Comedy-Horror Shaun of the Dead.
“Dude Where’s My Car” Comedy/Sci-Fi (people forget that it turns into a sci-fi movie toward the end involving aliens)
Superhero + Romance = Superman II, Spiderman II
Sci Fi + Horror = Alien
Sci Fi + War = Aliens
Sci Fi + Biblical + Prison = Alien[sup]3[/sup]
Superhero + Historical + War = the upcoming Captain America
Action + Comedy Die Hard
Without resurrecting the infamous Cafe Society Starship Troopers War, let me criticize this one by suggesting that it should be Science Fiction + Antiwar Satire. It’s clear that Neumeier intended it to be seen as satire of the space-war genre of movie, and that Verhoeven filmed it as such. Whether it succeeded in being good satire is debatable – I and others maintain it failed; Lissener and others that it succeeded. But what I think is irrefutable is that it was intended as sairical.
A faithful adaptation of the Heinlein book would have fit the traditional genre of (thoughtful) war movie, exploring the question of why human beings fight wars at some depth. There are several dead horses littering the CS landscape whose tombstones testify that the Verhoeven movie was not that faithful adaptation. I don’t propose to add to their number, just to suggest that the genre mix is rather other than you suggested in your post.
Thin, really thin.
Thank you, I’ve been trying to slim down.
That was actually a Zom-Rom-Com 
Something Wild took me aback when it changed from quirky comedy to violent thriller.
FTR, the screaming librarian scared the piss out of me when I was nine.
Some of the scenes in Dana’s apartment work effectively as horror: the eggs boiling on her countertop, and later the arms ripping out of her easy chair and holding her down.
From Dusk Til Dawn starts out as a shoot-em-up but finishes as a horror movie. It also has some comedy elements, with Cheech playing several roles.
The Time Travelers Wife