What constitutes a "shit rating?"
Big Trouble in Little China is 7.2/10 on IMDB, and it got positive reviews; it was, however, a commercial failure, making only half what it cost to produce. Great movie.
Wizards rates only 6.3/10 on IMDB, although it did well at the box office. That may be my favorite movie of all time.
Dredd failed at the box office but gets a 7.1 from IMDB. I think it's grossly underrated.
Star Trek: The Motion Picture is a 6.4 and generally gets poor reviews; it did fine at the box office. But I love that film.
If you want you get esoteric, Lord Love a Duck (1966) was a financial failure and gets only 6.3 from IMDB, but it's wonderful.
Disney's 1979 The Black Hole gets a 5.9 and didn't do well. It's a lot of fun and the ending is an acid trip.
The Prophesy (1995) got really bad reviews and 46% on Rotten Tomatoes, proving there's no accounting for taste. Absolutely worth watching.
Hawk the Slayer (1980), 5.3, is in the "it's so bad it's good" category. This includes Zardoz (1974), and Krull.
And, Dune (1984). 6.3 IMDB, total loss at the box office, and one of the best movies of all time. I kinda think Herbert might have hated it where he'd have liked 2021, but the cast, the atmosphere, the music, the hyperbolic representations of the characters; it is a masterpiece. And it features a young, mostly naked Sting (which is the lure I used to use to get my girlfriends to watch it).
S.O.B. (1981). 6.4 IMDB, but 81% RT. Box office failure. Hilarious, and a topless Julie Andrews (sigh).
Red Dawn (1984). 6.3/48%. Not my favorite movie, but worth a watch. Surprising decision to not utterly vilify (unhumanize) the Russian antagonists.