NPH referenced that back in 2011 at the Tonys. 
Have you seen “The Castle”? It’s an aussie “classic”.
I liked “Arsenic and old lace” and “The Ladykillers” (oldies but goodies, although they did remake the latter)
Seriously? Malkovich Malkovich Malkovich?
It’s certainly artsy, but it’s also hilariously funny. I enjoy absurdist humor a lot, so maybe that’s it.
“Dexter’s a chicken! Moo! Moo!” And Abe Vigoda! But yeah, you gotta be ready to not pay attention to the stupid plot and just go with the silly flow.
What We Do In The Shadows is one of the few recent movies that I found totally hilarious. Just go in blind and enjoy it. It gets better and better as it goes.
Zoolander is hilarious. Skip the sequel.
Some oldies, but in the same vein (madcap and a little bit blasphemous):
The Loved One (the original, and still the best, take down of funerals)
The Twelve Chairs (Mel Brooks before he started repeating himself)
Bedazzled (Peter Cook/Dudley Moore, not the pale remake)
Quick Change (look for Tony Shalhoub’s comedic brilliance as a terrified cab driver)
Gambit (If you want to see heist films taken down a peg, this is the movie for you)
Cold Comfort Farm (“There has always been Starkadders on Cold Comfort Farm”)
And one you have probably seen, but if you haven’t, I envy you. I’d like to be able to see it for the first time again and again…
Raising Arizona
Oh, and if you like the Coen movies, Fargo. That’s a corker, too.
A Midwinter’s Tale. Kenneth Branagh’s movie about a small cast of actors putting on Hamlet during the Christmas season in order to save a church.
The funniest movies I’ve seen:
Real Genius: mid 80’s movie starring Val Kilmer about a group of genius teenagers gathered together at a university. Kilmer is hilariously sarcastic throughout (e.g. “Do you run?” “Only when chased”).
Crazy People: this is an obscure 80’s movie starring Dudley Moore and Darryl Hannah. Moore is an ad exec who ends up in a mental institution. The patients help him with the ads (which use real products, and are absurd, e.g. “Jaguar. For men who get handjobs from beautiful women they hardly know.”), which are an unexpected hit.
Brain Candy: this movie was made by the same actors who did Kids in The Hall, which was a Canadian sketch comedy show. The movie is about the creation of a drug which makes people feel like their happiest moment in their life. The cast each play multiple characters. Simply brilliant.
Team America, World Police: this movie comes from the South Park guys, and was made in the midst of the post 9/11 Bush years. It’s a send-up of the War on Terror, so it’s not for anybody who would get offended at making fun of US hegemony (e.g. “America! Fuck yeah” is the hook for one song). But they do blow up Michael Moore. Also, it’s done with marionettes.
South Park, bigger, longer, and uncut: I’m not a particularly huge fan of South Park, but this movie was a very funny musical that made me laugh out loud. One of the songs was nominated for an Oscar (Blame Canada), but it wasn’t the best song, in my opinion- it was just the only one that wasn’t also profane. This is definitely a movie that mocks standards of decency, so you can’t be easily offended to enjoy it.
One of my favorite movie lines of all time: “WE BEAT PENECILLIN!”
I like that quite a bit. And given that Rat Race was mentioned, the OP might want to see It’s a Mad, Mad, Mad, Mad World. It’s what Rat Race was based on. Also, someone mentioned The Ladykillers and that was good. It was also one in a series of “Ealing comedies”, including Kind Hearts and Coronets and The Lavender Hill Mob. (There are others but I haven’t seen them.)
Good ones. If the OP likes those silly old brit comedies, The Big Job is another one.
Better off Dead
Dumb and Dumber
This is Spinal Tap
If you enjoy Shaun of the dead and hot fuzz, then I highly recommend finding the British show Spaced by the same people.
I assume you mean the 1968 3-part TV version, which is hard to find. The 1995 version just sucked.
“I saw something nasty in the woodshed.”
You should also round out the Cornetto Trilogy…The World’s End isn’t as funny as Shaun or Fuzz, but it’s funny.
I found In Bruges to be hilariously funny. Colin Farrell was great.
Sounds like the bowdlerized version with the swearing and “bad” language replaced (I think the Jag ad’ line should actually be blow jobs) - seek out the naughty version.
Horror movie ad line that didn’t make the polite version.
This movie won’t just scare you. It will FUCK YOU UP FOR LIFE!
Anyhow, funny film, just see the rude version.
Volvos: They’re boxy, but they’re good!