Recommendations

Male lead is a general who is extremely cold with a fearsome name to the public. Female lead is streetwise, active, cute and funny. Despite being fearful of the general initially, both ML and FL fall in love with each other.

Both dramas have the same FL and she is strong and powerful in both dramas.
Both MLs would die for her. Great fighting scenes, Especially in Legend of fu Yao.
Powerful MLs in both dramas. I must say the plots and costumes and set designs is better in Legend of Fu Yao. Great romantic scene in both.
( You would love it)
Great chemistry in both. ML is more playful in Legend of fu Yao while in Eternal love ML is more serious and gentle.
Both these dramas are my top favourite Chinese dramas. Master peace.

Similar, historical romance comedy type of drama. Although they may be similar each historical drama don't really have the same concept, mostly.

Similar vibes. Different story though. Revenge, infidelity and thriller. It is done really well and is as exciting and intense as TWOTM. A shorter drama but it packs it in. Great OST!

Both are Gumiho dramas. In Tale of Nine-tailed, ML is a Nine-tailed Gumiho. In My Girlfriend is Gumiho, FL is a Gumiho. Both showcase a sweet love story between the leads.

1. MLs are immortals. In Nine-tailed, ML is a gumiho. In YWCFS, ML is an alien.
2. MLs are waiting for his first love (which turned out to be FLs) from Joseon Dynasty.

These two share a lot of similar concept. Both MLs are immortal with supernatural power. ML met first FL when FL was still a child, in Nine-tailed: ML saved FL, in Hwayugi, FL free ML from his prison.

Similarities:
- The leads are childhood friends
- The FL in SIL used to bully ML and the ML in LIS used to bully FL in their childhood.
- Their chemistry is awesome. (It is the main thing that kept me going)
- Separated due to a misunderstanding.( In childhood)
- Love×Hate relationship.
Difference:
- SIL is a collage romcom, LIS is an Office romance

If you like childhood friends romance, then you may give it a try..

Similarities-
- Plotline - the 1000 yr old fox who is looking for his woman to be reincarnated
- ML who is someone who gives up responsibilities and is living like a vigilant
- Female Lead works in news industry: In M&V she is an aspiring journalist whereas in TTONT she is an Director for TV show
- SML is ML's Brother who keeps killing people and annoying ML
- common mythical references : liver eating, summer rain, blindness, one love etc
Differences
- M&V is more of romance centric whereas TTONT is mix of action, investigation, and horror
- FL is a lot stronger character in TTONT

The both have a spooky-like style and involves supernatural creatures (Hotel Del Luna involves ghost and the afterlife world while Tail of the Nine-Tailed deals more with mythological creatures such as the foxes, etc.).
The male lead of Tale of the Nine-Tailed and the FL of Hotel Del Lune both are more than 1000 years old and have a past that ties with someone important that they have lost.
Also the concepts of reincarnation and past lifetimes are an overarching theme in both shows.

1) Both include supernatural beings (Gumiho / fox spirit) as the male lead
2) Both of them have romance, humor, hidden identity & re birth
While Tale of nine tailed takes place mostly in the modern world, Gu Family book is set in the historical era.

Similarly hollow feeling to the stories. Both are captivating and easy to watch with very nice cinematography.
The main actor of “Tale of the Nine-Tailed” is also one of the main characters in “globin”, there’s even a reference to it on “the tale of nine-tailed”.
Both story’s talk about the first and only love. Both are fantasy/supernatural genre, although “the tale of nine-tailed” seems to be a little darker, in terms of cinematography.

Ignoring the fact that their names are also very similar, these two both one supernatural lead and a regular human lead for the other.
They both have reincarnation plots as well as villains who were present in their past lives.
In both of these dramas, the main lead is very confident in his abilities.
Tale of the Nine-Tailed is about a nine-tailed fox looking for his reincarnated lover and meeting a paranormal show PD.
Legend of the Blue Seas is about a mermaid who meets her lover from her past life who is a con artist in his current life.

Both dramas share similarities in the storyline and the nature of the relationship between ML & FL are the same: the FL was adopted and the ML swore to protect her. However, as they grow into teenagers, they become a bickering pair. ML develops romantic feelings for the girl who was raised to be a "sister", although they share no blood relationship. ML becomes protective and is constantly warding off all boys who get too close to his "sister".

It can be compared to " Our times " in the aspects like youth, passion , a life changing incident and love. Even though both of them have a different messages to convey, the cast in both the movies are exceptionally good which makes it worth watching. it was like they lived through the characters , i am damn sure that at least one of the scenes might have made an impression on you on different ways of viewing life. it is just a suggestion of mine.
watch it or not depends on you. a wonderful portrayal of lives awaits you. =)
HAPPY WATCHING!!!