I'll post 4 of them.  Post your picks, and also comment on my picks, if you want.

John Carter, Around the World in 80 days (2004 edition with Jackie Chan), Aliens vs. Predator: Requiem, Flowers of War (Christian Bale)

John Carter--very entertaining to me, I really don't know why this movie bombed

Around the World in 80 days--I was laughing pretty hard at the goofball moments, and it had some of Jackie Chan's best fight scenes, maybe not stunts (can't beat Police Story 1 and 2), but his fight scenes were pretty good.  It was very entertaining to me.

Aliens vs. Predator: Requiem--for what it was, it was great mindless body count fun!  I liked it better than the first movie.

Flowers of War--a couple of the poor reviews were by critics who obviously didn't know the history of the Nanking massacre.  Roger Ebert wondered why the priest couldn't be an Chinese priest instead of Christian Bale's Caucasian character, well I think that Ebert didn't know that the Japanese had contempt for all Chinese people, and so a Chinese priest couldn't have served as a shield for the young Chinese girls the way an American priest would (this was 1937, before Pearl Harbor, so the Japanese soldiers didn't have contempt for Americans yet).  I thought it was a powerful and poignant film.

So what movies do you think had unfair criticism?

None

I never watched a movie in my life that received negative reviews and end being good

Speed Racer was perfect for what it was supposed to be.

^ basically this.

I dont buy into the "its so bad, its good" stuff.
Or "mindless action fun".

Basically if a movie is hated by critics, its almost certain its just a bad movie.

IKR? I understand a mixed/divisive movies being good depending on who is watching  but a movie that over 500 people watched the overwhelmingly majority hated it? Hard to believe it's good 

I really like The Green Hornet. Thats a movie nobody seems to like.

There's so many to choose from. Twin peaks: fire walk with me, the shining, predator, Highlander, saw 1, The thing (many other John carpenter films), starship troopers and many more

Wow, just no to all of this.

I've not watched the above movies but consider these:

The hangover III and Expendables III

I guess it depends, if you talk about panned films that are still to this day considered bad by critics - I cant think of any at the moment, but I know theres some. Much of my concept of what constitutes a genuinly good film depends a lot on the technical aspects of the film. Direction, cinematography, dialogue, etc; and those aspects usually are what critics take into consideration for their reviews, so I tend to agree with them... mostly. Its easier to find examples of the opposite for me, "movies that were praised by critics but arent that good". 

So sure, theres a lot of poorly reviewed films that are enjoyable, specially in comedy, a lot of average films that sort of trascend the medium and become a cultural trend, a lot of "popcorn" franchises that sell a lot, but yeah, rarely they'd be what I would call a good film. 

But as with any art form, theres revisionism because perspective and understanding changes with time, films like The Shining or The Thing were poorly received when they originally released and are now considered almost masterpieces of their genre, something I agree with, cause they are that good. 

"Too bad they're good" is an entirely different thing tho. These are bad films - its in the name. We just find them enjoyable because they're ridiculous. Like, Tommy Wiseau's The Room or 2006's Wicker Man.