Take a modern movie back to 1930

I think that would run into all sorts of problems with the time-space continuum!

The Three Amigos.

Up until the discovery of the wreck in the eighties it was generally assumed the Titanic sank in one piece, so the audiences of the thirties might be wondering why the ship splits in two for this particular film.

Other than that (and the bits that would need a little censoring), Titanic would be my choice too.

It’s kind of a shame that the OP as setup only runs back to 1990, because I think something like Raiders of the Lost Ark might do well. Only problem, of course, is that it’s set in 1936 and needs Nazis. So maybe Temple of Doom would work better.

But going with the constraints of the OP, how about something like the Wallace and Gromit shorts or movie or maybe Chicken Run? After all, Chicken Run is just The Great Escape (which of course hasn’t come out yet) with chickens.

A possible complication for the OP. Widescreen didn’t really exist in 1930, and we’re looking at something between either 4:3 or the Academy ratio of 11:8.

The Mask of Zorro, the Antonio Banderas version.

Nothing in it that isn’t perfectly familiar and comprehensible, or unusually spectacular, but is nevertheless thoroughly entertaining and will thrill and excite.

My gut reaction is Dead Men Don’t Wear Plaid just for maximum mind-fuck potential.

If the object was to make them think it was made by magic or a deal with Satan, I’d go with either Terminator 2 or Jurassic Park.

If the movie could have been taken to the 40’s, “the good German” would be perfect. it was supposed to be like something filmed after the war.

I wonder how well any of the movies mentioned so far would take to being shown in black and white?

a trifecta of mel gibson: Braveheart, The Patriot, and Passion of the Christ.

I dunno, the severed head in the wine jar might not play well.

Note that you’d probably have to eliminate any movie with cell phones.

Dead Men Don’t Wear Plaid is a black and white movie.

Yeah, I think graphic violence is going to be a stumbling block for a lot of films. Now that I think about it, Last of the Mohicans wouldn’t pass muster on this ground either.

When Steven Soderbergh’s Traffic and Erin Brockovich were both nominated for Best Picture Academy Awards in 2001, the Washington Post ran an article about the two movies. The writer said that Erin Brockovich is a pretty standard plucky-hero-fights-corruption flick, the kind of thing Enrst Lubitsch might have directed. The difference being the hero is a she. The writer went on to say that Traffic’s structure as a film would have been completely foreign to people of the 1930s or 40s.

To the OP, I don’t think either of these films could have been shown in 1930. Traffic was about drug dealing, and Erin B. depended too much on Erin’s profane language and use of her sexuality to manipulate men. I don’t think even this relatively mild exchange would have passed a 1930 censor:

Ed Masry: What makes you think you can just walk in there and take whatever you want?
Erin Brockovich: They’re called boobs, Ed.

Hmm - was Mae West enough of an actress to pull off the role of Erin? The script would have to depend on many euphemisms and many perfectly raised eyebrows. Mae was 37 in 1940, might have worked. Oh yeah, the OP is about taking completed movies to 1930, not scripts.

Looking over IMDB’s top 250 list, and just counting movies made the last 20 years (1990-2010), my nominees are:

Lord of the Rings trilogy - but too long for 1930, they didn’t do sequels as much then, the books hadn’t been written yet, and it suffers from the “how’d they do THAT??!!” syndrome discussed above. Nonetheless, an amazing adventure trilogy IMO.

Spirited Away (2001) - with edits it would be the next Snow White. Since it’s animated there’s no “How’d they do that?” concern. Would a 1930 US audience sit through an animated foreign film? I just checked - Snow White was 1937. Spirited Away would blow Disney out of the water before he got started.

So would Ponyo (2009) and it’s a more accessible flick, more family friendly.

LA Confidential (1997) - if it could survive the Hayes Code. Naw, it barely worked in 1997. Too bad, it’s a great film.

Gladiator (2000) - minimal changes, but how did they film the fight with the live lion??

The Sixth Sense (1999) - mentioned upthread

Groundhog Day (1993) - but would the scene where Bill Murray “breaks the spell” be allowed in 1930?

Finding Nemo (2003)

How to Train Your Dragon (2010)

Ratatouille (2007)

IMO, animated movies would work best going from 1990-2010 to 1930, although things that were obviously computer generated might puzzle the audience. Lilo & Stitch would work as far as the animation goes, but the story depends too much on Elvis’ songs (not written in 1930!), and a 1930 mainstream continental US audience might not accept a story about a pair of native Hawaiian orphans and their pet alien.

Pixar’s animated shorts: GOLD!! Best of a good bunch that would travel well to 1930 are, IMO: Luxo, Jr; Tin Toy; Knock Knack; For the Birds; and Presto. The first three were made before 1990, but I’ll sneak them in the OP’s time machine anyway.

A lot of violence would have to be cut from the first two. I have not seen Passion, but from everything I heard about it there is no way it would be show-able in 1930.

I realized a bit after posting the OP that there’s the color/BW issue which I’d prefer to ignore because it more or less instantly wipes out 99% of movies. So I’ll just say a wizard did it, and color/BW is not an issue.

But aside from that, if your answer is “movie X, but with scene Y censored out”, that’s perfectly fine, if less pure than an answer with no censorship.
But I don’t think Titanic works at all. First of all, it has quite a few scenes in modern times, and taking them all out would destroy the flow of the movie entirely. Also, the special effects are just WAY too good. Same for 2005 King Kong.
The best answer I came up with is Crouching Tiger, Hidden Dragon. Nothing in it couldn’t have been done in 1930. It would seem alien and different, certainly, but I can’t imagine people wouldn’t have been just as captivated then as they were today. Another choice might be Amadeus, although while it might pass muster for being believable, it’s a bit too much of an art film to be a huge smash hit.

Master and Commander
Topsy Turvy

Just wanted to point out that color films did exist in 1930. It wasn’t common because the coloring processes back then were difficult and expensive but people wouldn’t have had a hard time accepting the existence of a color film.

Since the OP mentioned the last 20 years, I’d have to go with “Pearl Harbor” although I’d prefer “Tora Tora Tora”. Imagine what all of the people who see it will think on 7 December 1941.

Since audience appeal is important as per the OP, and since there’s no mention of the movie having to meet the standards of whatever censoring authorities were around at the time, I’d bring L.A. Confidential. It’d be futuristic to people in the 30’s, but not outlandishly so, and it’s got the kind of plot that would appeal to audiences of the ganster era.

Musicals were big, so maybe I’d bring Moulin Rouge. Nicole Kidman in lingerie is probably like nothing 1930’s audiences had ever seen before.

How about Sky Captain and The World of Tomorrow?