Which Gong Hyo Jin show should I watch?

Her acting is really on point in It's Okay That's Love, and her chemistry with Jo In Sung is beyond perfect. My all time favorite!!

I haven't watched "The Greatest Love" but out of the three others, I would recommend "It's Okay, That's Love". If you like somewhat more realistic (+psychological) dramas, that is. You'll end up loving all the characters and their imperfections. Also, I really liked D.O's acting in it even though I'm usually not very impressed by idols' acting (there are some exceptions though, most of them being slightly older idols).

"The Master's Sun" is also pretty good; not my favorite but definitely a must-watch!

i would personelly recommend "Buiscuit Teacher and Star Candy". Even though it's pretty old. It is still my favorite Gong Hyo Jin Drama. "The Greatest Love" was damn funny and i loved it a lot. i have the Drama "It's okay, that's love" on hold for now. Mostly because I'm not sure if i like Gong Hyo Jins character here. "Master's Sun" was a solid drama with a lot of suspense (i normally don't like horror so this was already enough for me) and really nice heartbreaking and heartwarming side stories. But i didn't like the male lead. He was just frustrating. "Jealousy Incarnate" infuriated me. The character of Gong Hyo Jin was really frustrating and the male lead a total asshole at the beginning so i put it on-hold after 4 Episodes. I'm not sure if i will pick it up again. For now I'm not in the mood for that. 

And after writing all this i see that your post is already three month old. *chuckle* ;)

Master's sun is my favorite drama of her. 

For me, as to order it would be:
1. It's OK, That's Love

2. Master's Sun

3. Jealousy Incarnate

I haven't  completed The Greatest Love yet, for some reason I never got past the crucial first 2 episodes and need to rewatch.  I recently watched Pasta- would put it at a lower #4 for me, while 2 and 3 are both excellent.

• the master's sun
• pasta