I recommend Rooftop Prince and Faith first. Rooftop Prince because this drama is a complete package, drama, comedy, fantasy, action and romance, also bromance. Lol next is Faith, if your friend knows BOF and liked it, or he/she likes LMH, this a great drama as well. P.S. i hate historical dramas but this time travel dramas made me love historical dramas because somehow, the fantasy add some spice to Korean History and made it more fun and interesting. ^^