Several musicals come to mind (not all of which have been made into movies) in which a character announces “I… am… dying… but first a song, maestro if you please! Ah one and ah two…”
MAN OF LA MANCHA= Don Q is on his deathbed unable to remember anything… except a foot stompin’ medley! “I am I Don Quixote…” ending with "whithersoever they blow, onward to glory… OH ELIZABETH I’M COMING TO JOIN YOU BABY!.. I go [plop]
EVITA- she’s dying of cancer but not before she sings her final testimony to the tune of A Cinema in Buenos Aires.
CAROUSEL, WEST SIDE STORY, OKLAHOMA- all have choreographed deaths.
LES MISERABLES- the musical’s not a movie yet, but at least three of the buggers do this, one while shot through the lung, while Valjean sings to a dying whore a very polite “would you die already! The fuzz is coming any second!”
REEFER MADNESS has a funny homicide (the pistol and the framing)
ROMEO & JULIET- I don’t dispute that when it came to dialogue Billy Shakespeare took dictation from the gods themselves, but when it came to plots he was on his bloody own. That whole last scene is just an exercise in stupid drama queens trying to outdo each other. NOBODY CAN NOTICE THE OTHER ONE IS BREATHING! THAT WAS THE BEST THE PRIEST COULD DO-- “I know, let’s tell your parents you’re dead and we’ll bury you alive and after a nice nap you’ll pop an Adderall and be up and dancing… around a bunch of rotting corpses, but we’ll cross that bridge- oh, and let’s not tell Romeo, he’d ruin the surprise”. For that matter every Shakespearean play with a character who walks on stage twice or more to say “Y’all ain’t gone b’lieve who just died backstage!”
The aliens in SIGNS. They can cross light years of space to attack a planet (for no obvious reason) but don’t realize “I don’t like H20”. WAR OF THE WORLDS isn’t much better and the virus upload that leads to the alien deaths in INDEPENDENCE DAY is arguably more stupid.
The TV series DRAGNET (not a movie, but I’ll count it anyway) once had a character who died of an LSD overdose.
SUNSET BLVD would, imo, have worked better if you hadn’t known whose body was in the pool at the beginning. I know about the original version of the opening (the talking corpses in the morgue saying “how’d you get here?”) but I think it would have been better to have the audience asking “Is it Joe? Norma? Max? Betty? Another monkey? Who?”
The woman who dies of a poisoned dress in the Cate Blanchett movie ELIZABETH. I know it was in Medea, but is that even possible in real life?
The poisoned cannolis in GODFATHER 3. Just clip the old bastard. He’s 90 and walks with a cane, how hard can he be to kill? A 3:15 a.m. phone call or being overcharged for his linguini would probably give him a mild coronary.