Star Cat (Crossing the Streams!)
Catbusters
The Great Catsby
Catman: Dark Cat
Gatoblanca
Gatoca
Herbie the Love Cat
Fast Cats at Ridgemont High
Cat to the Future
Gone with the Cats
Catfellas
Dances with Cats
Mad Cat: Beyond Thunderdome
Trading Catboxes
Cats (The Musical: In space no one can hear you yowl)
Cat Hur
300... Cats
The Trojan Cat
O Cat Where Art Thou?
Lord of the Cat (obviously, a work of fantasy)
Hairball (the musical)
Frisky Business
Cat on a Hot Tin Cat
I suppose "Catfellas" could have been "Goodkitties".
"War and Cats" lost out to the 500 char limit.
More:
Some like it Cat
Dr. Strangecat
Giant ... Cat
Birth of a Cat
The Little Tuxedo Cat (homage to Catlin, erm, Chaplin)
Cats on a Plane
Catnado
Les Cats
Jesus Christ, Supercat
A Cat Grows in Brooklyn
Death of a Salescat
Anthony and Cleo the Cat
Night of the Living Cat
It came from beyond the Cat
From Russia, With Cat
The Planet of the Cats
Supercat
Cat House
@dredmorbius Cat Runner
#ReplaceMovieTitlesWithCats