All of them.

Melania

Lot of interesting answers here, but for me, the obvious choice is "Willy Wonka and the Chocolate Factory"

Rambo, Duh.

I would love to see him as a John Wick style character.

Alternatively he and Jack Black could bring back the Blues Brothers

The Weird Al Movie. Haha jk Dan Radcliffe did a great job.

Being John Malkovich.

Idk about better but I need a LOTR trilogy like this.

If they remake Spy Hard like they did with Naked Gun, let him do the theme song and the lead role.

UHF.

That movie would be unwatchable with anyone else

American Psycho

Edit: I had almost forgotten about this: https://youtu.be/Fk15H6PjBis

yes

are we talking 80s dorky al or today's "can pull off serious" al?

if it's the former, death wish 3.

if it's the latter, mandy.

Titanic with Al as Rose.

Annie, the musical.

Joker (2019)

Fight Club as the narrator. Easy to imagine him snuggling Bob's giant tits.

Project Hail Mary

highlander 2. There's no way it could be worse.

Eyes Wide Shut

James Bond. At least the recent ones.

Star Trek The Motion Picture, but with Weird Al as V’Ger.

Die Hard would be fun

Backdoor Sluts 9

Orgazmo

Justice League, but with Weird Al as Wonder Woman.

Muppet Treasure Island, but only if he played it straight like he was actually Kermit

The Hobbit trilogy

Evil Dead 2. The original.

Instead of a chain saw, he replaces his hand with a floppy accordion and smashes the tree demon on the head with it.

Eraserhead.

Mean Girls