This was a show that had it all: romance, action, drama, comedy, eye candy, bromance. This is one of the few shows that I can watch repeatedly, and catch something new every time.

STORY/WRITING: I was so impressed with how this show was written. There were some seriously swoon-worthy lines, but I think what I loved the most was the comedy aspects of it. In the midst of a show with serious stuff going on, there were many refreshing moments of humor. The writer was able to continuously change gears so we, as the viewers, were never actually able to settle in comfortably. The action was interspersed throughout all the episodes, so there were no draggy periods, and just when you think you can't handle the stress, something funny would happen. The four main characters were written so well and they meshed together, playing off one another in a real way. The bromance between the two male leads was very engaging, as was the relationship between the female leads that resulted from a bad situation in their past. And the conversations when the women took sides against the men were a hoot.

ACTORS/CHARACTERS: Song Joong Ki as Yoo Shi Jin. He fit the mold of romantic lead perfectly, and when I found out he had just been released from the military three months before working on this show, I could understand why he seemed so comfortable in the role of a soldier. His character was very principled, loyal, and dedicated. He loved his country and he loved Kang Mo Yeon. He was fiercely protective of her. There were many, many moments of intense staring by him as he looked at her, and when you couple that with his boyish good looks and charm, and you've got the whole package. He was just so likeable.
Song Hye Kyo as Kang Mo Yeon - this was a difficult character for me. She's a wonderful actress but I often didn't like her character. She was a doctor and strong because of that, but in relation to Yoo Shi Jin, I felt that she was too wishy washy. She would tell him things that sounded like she didn't want to get involved, yet she flirted. She wanted everything to be black and white, when often life is shades of gray.
Jin Goo as Seo Dae Young - at the outset, you might be tempted to think that this character is cold and unemotional. He, also, was very protective of the woman he loved. Jin Goo was excellent at showing such depths of emotion with just the expression in his eyes.
Kim Ji Won as Yoon Myeong Ju - I've seen this actress in a couple of things and she plays the bitchy woman well. She is, to a certain degree, the same in this role. She's strong and knows what she wants, and does what she can to achieve things, while bucking up against circumstances trying to hold her back.

CHEMISTRY - I cannot say enough about how good the chemistry was between the couples themselves and the friendships they had with one another and the people that they worked with, both the soldiers and the medical staff. I was not overly surprised that the main leads had gotten married in real life following making DOTS. Sadly, they divorced last year.

OST - though there were a few times that I felt that the music was overly dramatic, for the most part it was terrific. Some of the same artists did excellent music in Crash Landing on You as well. There was one part in the show when the main song, rather than using vocals, was played on the cello and it brought such beautiful emotion to the scene.

I do have to say I didn't like the ending, the feel completely broke from the rest of the show and was just silly. Also, I know they have medical advisors for these shows, so why is the medical stuff always so inaccurate? How they do CPR, what they do to save someone after drowning, how when a patient pulls out their own IV it never hurts and it never bleeds. This is certainly not the only drama guilty of this.

I watched his show when I first started watching Asian dramas, and it's still as good after having seen it numerous times.