I didn't see the trailer or commercials for it before seeing it. Just came across the poster, read a one sentence description and decided to give it a shot.
I watched the trailer afterward and it truly doesn't give justice to the film at all. The trailer comes across corny and cliche, but the film is anything but that.
With the way Wonder is crafted, acted, and edited... I was honestly blown away by it. Give it a shot on a gloomy day.