This is a spinoff of the “worst movie you ever saw” thread.
The first one that comes to mind for me is a forgettable comedy that came in in the early 1990s called “Splitting Heirs”. It co-starred Rick Moranis and was totally panned by critics; I went with a classmate, who like me was an art movie aficionado, after finals were over because we wanted to see something mindless, and even though we figured out all the plot twists way ahead of time, LMAO’d all the way through it.
p.s. If this is how you feel about “The Rocky Horror Picture Show”, it’s OK to say so. 
Flash Gordon. It’s pretty much objectively awful in every way, and I don’t normally like any movie that’s “so bad it’s good”. But this movie, I like.
“The Manitou” One or two nifty special effects, one super disgusting one, and a bunch of (at the time) name actors who had no idea what they were doing. A total mess; loads of fun.
Pacific Rim. I’m not sure if it’s a great movie cheesily done or a cheesy movie done greatly. Fighting Power Ranger transformering robots against dinosaur Godzillas bashing each other’s heads in with ocean liners and whole subway trains? How could that be anything but terrible? How could that not be great?
“But I’m a Cheerleader” – This movie was very poorly made; filled with stale jokes, trite cliches, and obvious “twists”; and for the most part seemed particularly smug and self-satisfied with itself. But I have to admit that the ending won me over.
Billy the Kid vs. Dracula, with John Carradine and Virginia “Mrs Olsen” Christine. One of the great steaming turds of all time! 
Congo was a pretty stupid movie, but I thought Tim Curry and Ernie Hudson were funny. Furthermore, I think all movies should end with the heroes shooting gorillas with a laser made out of a giant diamond.
Okay, this is weird, because this is the one I was going to say too. I didn’t think many people had ever heard of/seen it. But I love it! It’s so terrible, but I Tony Curtis’s character is great.
Honorable Mention: “Xanadu.”
Nothing But Trouble.
For some reason North is considered one of the worst movies ever, especially by Roger Ebert. But I really enjoyed it. I just understood the comedy level it was going for and thought it nailed it.
Similarly I knew what they were going for with Mortdecai, which was Johnny Depp trying to make a Terry Thomas movie, and all it needed was an Editor that understood comic timing to make it work. Unfortunately Hollywood doesn’t seem to have any such Editors anymore. But I liked it anyway.
Going by IMDB, my favorite movie with a terrible rating is Furry Vengeance. Seeing Brendan Fraser abused by cute animals is great even if the plot is bad.
I love flash gordon. I love The bad acting. I love The stupid plot. I love The terribly confusing physics. I love Brian Blessed. And of course, I love the soundtrack!
Fun fact: hans zarkhov’s assistant Munson is also porkins in star wars and the top…men guy in raiders.
I took my grand son to see ‘Wreck it Ralph’ It was really cute.
Well, from the other thread, I like Joe Versus the Volcano.
And also Meet the Feebles. It’s kind of like the original Muppet Show, the backstage antics of a theatrical troupe of puppets; except that if they weren’t puppets this movie would get a hard X rating. The emcee is dying of every sexually-transmitted disease in existence. The knife thrower is strung out on heroin to suppress his flashbacks of 'Nam, and the diva goes on a killing rampage with a machine gun. I don’t usually go for graphic humor if it’s just done for shock value, but there’s something about the combination of the utterly profane and puppets that just makes me laugh.
And it was made by Peter Jackson, who went on to do The Lord of the Rings.
I just watched one on Amazon the other day called “Killer Donuts” (or something like that). Anyway, it’s about these donuts that come to life and eat people. So horrible, but damn, I couldn’t stop laughing.
Also, the only reason I know Hudsucker Proxy is an awesome movie, is because I was too lazy to get up and change the channel when it happened to come on my TV.
And they say laziness doesn’t pay off.
Wreck it Ralph is factually a great film and does not belong on this list of stupid movies you end up liking.
What? You’re kidding me. It wasn’t very popular in the kiddie set. There is hardly any merch. I looked for tee-shirts or pjs for the boys with wreck it Ralph. No luck. YMMV.
ETA as the OP asked, I ended up liking it!
There was something screwy going on with this movie. I think I had to wait like three years just to be able to rent this movie.
I think they may have had some issues with licensing or something. (My WAG)
A legitimately terrible movie that I have a bit of a soft spot for - Wild Wild West. Yes, it is made of dumb, with dumb filling and dumb on top, but it has Will Smith and Kevin Kline in it, so how bad can it be really?
Probably didn’t pay for any particularly nice houses though…
Nothing can touch Plan 9 from Outer Space.