I will let you decide what defines a bad movie.

For me, what makes a movie bad is lost potential. Good actors in a bad story, bad actors in a good story. Big budget wasted, bad directing, cliches, bad rehash/copy, fanservice.

B-movies like Sharknado are not bad in my eyes, beacause they are made dirt cheap and actually make fun of themselves. This applies to low-budget movies in general.
Also, these include only the movies i have actually seen, not the ones that are supposed to be bad/good.

So here is my list.

2010 - Kick-Ass (I can't believe people think this *beep* is funny)
2011 - Green Lantern (Do i even need to comment)
2012 - The Impossible (So much talent and money wasted on this piece of crap!)
2013 - The Wolf of Wall Street (I don't know where to start. Utter waste of money and talent on this *beep*
2014 - Predestination (Tries to be smart, failes miserably, yet people think it's smart due to cliche grandfather paradox)
2015 - Jurassic World/Terminator Genisys Tie - (Shamless shameless shameless moneywhores, exploiting fans with poor rehash of old masterpieces).

Brave
Dracula Untold
Filth
Godzilla
Last Knights
Man Of Steel
Red Dawn
Whiplash

All conclusive proof that there is a God, and He really hates us.

2010: Furry Vengeance, I rated it when I saw it, gave it a 1, all I remember is that it was really bad.

2011: Megan is Missing, looks like an amateur film, bad non-acting, and incredibly awkward and unrealistic writing. No subtlety to be found.

2012: Joyful Noise, Dolly Parton and Queen Latifah are annoying as hell, and the drama was laughable and forced.

2013: Scary Movie V, Movie 43, A Haunted House, and Best Night Ever represent everything wrong with Hollywood. I almost don't even want to acknowledge these as movies.

2014: Transformers 4, bloated, boring, over the top, and obnoxious.

2015: The Walking Deceased, see my 2013 description.

2012: Joyful Noise, Dolly Parton and Queen Latifah are annoying as hell, and the drama was laughable and forced.

Holy crap, Dolly parton and Qeen Letifah in the same movie, must be *beep*

2010: The Last Airbender (1/10)
2011: Spy Kids: All The Time in the World (5/10)
2012: Breaking Wind (1/10)
2013: Stranded (5/10)
2014: Humshakals (1/10)
2015: The Age of Adaline (9/10).

Incidentally, 8/10 to Green Lantern and The Wolf of Wall Street.

I'm only counting cinema releases as well otherwise it gets too easy to pick on SyFy channel movies.

2010- Alice In Wonderland
2011- Battle Los Angeles
2012- Ghost Rider: Spirit of Vengeance
2013- G.I. Joe: Retaliation
2014- The Expendables 3
2015- Poltergeist

"Megan Is Missing" is supposed to look like amateurs. It's a found footage movie. If it looked like a Hollywood production, the aesthetic wouldn't work.

And no, subtlety wouldn't work in the films storyline.