I would choose A Korean Odyssey.

Obviously the two shows are different and where one is a historical drama, the other isn't. However, they both have Lee Seung Gi playing the ML who is non-human.

Story: Don't get me wrong, I thoroughly enjoyed GFB and I didn't find myself bored or wishing for more throughout it. It didn't feel draggy and I don't feel as though it was lacklustre when it came to the romance - as other reviews have suggested. In some ways, this was a lot better than AKO and I also loved the communication and chemistry between the leads in this a lot better. But the ending did kind of ruin it for me (and not for the reason a lot of people probably think). I want to keep this spoiler free so I won't say anything except that it wasn't as beautiful and magnificent as the rest of the drama. Sure, there were plot wholes if you look closely, but that never took away from my enjoyment. Plus, I appreciated the amount of loyalty and trust present within the friendships/relationships. It was a nice break from other dramas that are built on miscommunication, misunderstanding, and lack of trust.

Acting/Cast: This drama was perfectly casted in my opinion. Most of the actors did amazing and even though I'm not really a fan of Bae Suzy's acting usually, this was probably my favourite performance from her. But that might have something to do with Lee Seung Gi being her partner; they had really great, believable chemistry.

Music: It was good but not amazing? It did it's job at the right moments and all that, but I've heard better soundtracks.

Rewatch Value: I gave this a 5 because of the ending and slow burn romance. It's not really something I think I would find myself rewatching. In saying that, I'm not someone who rewatches shows often anyway.

Overall: I would say this is definitely worth a watch. I genuinely love the drama and loved the experience of watching.