But if there's one thing I respect Rain for, it's that he really tries, and most of the time he does a good job. I always say that you're born with talent, that no matter how much you practice you will never have the spark that truly talented people have, but to a certain extent, Rain is the very contradiction of that statement. When he started out he wasn't the best singer and he still isn't, but you listen to his recordings and then you listen to his voice live - he doesn't hide the fact that he isn't the best singer since anyone. And that's why I think he's gotten better over the years, because he never masked his (in)abilities and he let them develop and strengthen in time.
One is the perfect example of how much he tries to deliver, and how little he tries to cover up. You don't hear any forced or auto-tuned high notes he can't hit in real life, no extra-padded lines to the point where you can't hear his voice, and no overpowering instrumental hooks. The song may seem very generic, but that's just one dimension of the song. The melody is all within his comfortable range, and any higher notes he hits aren't pushed - everything comes out naturally.
It's for that reason that this song is in the top 50. A song is half construction and half execution, meaning that how you deliver the song, how you sing it, is just as important as notes and chords and transitions. A good song is not a good song until someone executes it at a level up to par with how it was put together.
One may be a tad bit generic at certain places, but the sort of "harmony" between the construction and the execution make it one of the best songs for me this year.