Tale of the Nine-Tailed
I almost dropped the show so many times because I didn't care one inch about the plot (big boss monster villain to defeat is kind of juvenile and you know exactly how that goes) and the writing was a mess. But I stuck through for other things. Even though the romance didn't make me cry or squeal, I loved the main two characters as individuals and liked that they were happy with each other.
More importantly ...
As everyone points out, the bromance steals the show. Actually, Lee Rang as a whole does. When you can sense a character that's annoying you is probably going to grow on you even AS they annoy you ... chances are, they're gonna turn into your favourite part. I wish we got even more of his and Lee Yeon's moments in the past. Sidenote: I need more purely platonic friendships between guys and girls in dramas! This was one of my favourite scenes, I kid you not!