In some cases, you might just be writing from the wrong point of view.
Maybe its not a problem with the story itself. The world could be well crafted and the plot tight. All of the characters, including your MC, could be perfectly interesting. But maybe they're just in the wrong place to shine. Maybe you're just not observing your story through the right eyes.
Point of view makes a big difference in the direction of a story. J.K Rowling, for instance, did herself a big favor when she wrote about the wizarding world through the eyes of Harry Potter. Because Harry was new to everything, he had a lot to learn and the audience was able to learn along with him.
Suzanne Collins wrote the first third or so of Hunger Games both in third person and first person POV before deciding to take a more personal approach and rooting her story directly in Katniss' head. Both J.K. Rowling and Suzanne Collins made the right choice for their stories.
So what's the right choice for yours? Well, for one thing, that's up to you. First you have to decide which character will tell the story best, especially if you plan on a limited point of view. Maybe you want to tell the story from multiple views or maybe just one, but whatever the case, your point of view characters will determine how the reader sees the world of your book.
Let's take a look at a few possibilities of point of view and their advantages.
First Person Limited- This can be an excellent and extremely difficult POV to write from. On one hand its very personal. We relate very closely to the character and see everything through their eyes. It often allows for more experimentation with the character's voice as well. However it does limit the views of other characters and, if the reader doesn't like your main character, they'll have an extremely difficult time getting into the rest of the book. Examples include- Divergent, Twilight, Hunger Games, the Gallagher Girl Books, The Fault in Our Stars, etc.
Multiple First Person- Like the previous POV, this allows you to get personal with your characters, but this time with multiple characters. This can help you see the story from multiple different angles, as well as give readers options if they happen to not like one of your MCs. But, on the other hand, its very hard to pull off multiple first person POV without all of the characters sounding the same. Differentiating voices takes a skilled hand. Examples include the later books in several series, including Matched, Divergent, and the second Percy Jackson series I find a lot of books don't attempt this until after the first book. But that doesn't mean it can't be pulled off. Legend by Marie Lu does a great job with it.
Third Person Limited- This isn't quite as personal as first person point of view, but it allows a bit more flexibility and its still possible to get a lot of voice out of this. But since it is limited, it still restricts you to how your MC views the story. Examples include Harry Potter, of course, Wrinkle in Time and Cinder but there aren't, I find, a lot of third person books that don't jump heads a lot. Harry Potter is one of the few limited third person books that sticks to one head.
Multiple Third Person Limited- Boy is this a common one. While not being personal, it allows you to cover a wide range of characters and tackle the story from mutiple angles. Now, pulling off too many characters and keeping them focused and interesting takes practice, but this is the favorite style of many writers. Examples include: Mistborn, Vicious, Inkheart, Daughter of Smoke and Bone, Night Circus, The School for Good and Evil, The Gone Series, A Song of Ice and Fire and about a million other books.
Third Person Ominpotent- This style has been fading as it was much more common in older works. Its a kind of impersonal style, told from a perspective removed from the main character but it can work if in the right hands. Examples include Les Miserables, Lord of the Rings, and a Series of Unfortunate Events.
So what style works best for your book? You might have to try out a few to figure it out. But once you do, it'll be worth it. The POV of a story can make all the difference.