Let me add one lol. I have tons where the ending has been totally unsatisfactory but I'll go with..
10. I Feel You Linger In The Air
That was a relatively happy ending by all means, him meeting Yai's descendant who sort of carries Yai's memories and knows of their love story in the past? It was brilliant. This was the person who had hired him to work on the old house, it was all set up from the beginning, it was perfect.
Only problem? None of this was actually revealed in the series itself. I had to go on a wild goose chase to find that this was the ending of book 1, which brings me to my next point.
Where is the sequel they set up??!