10 Starfleet Medical Officers Ranked
Nurse Chapel (Majel Barrett) appeared in many TOS episodes, and usually in her professional role to assist Dr. McCoy. Unfortunately, the only two times in the series that Chapel was shown as more than just a nurse, she became the victim of gender clichés of the 1960's, in "The Naked Time" (her unrequited love for Spock) and "What are Little Girls Made of?" (her unrequited love for Korby). It is satisfactory that Chapel has an MD degree by "Star Trek: The Motion Picture", although we don't see much of her because she is once again subordinated to McCoy.
9Leonard McCoy (Kelvin)
Despite the timeline split, Kelvin McCoy (Karl Urban) is much like his counterpart in the Prime Universe. The divorce mentioned in "Star Trek (2009)" is one additional rationale for his sarcasm that occasionally resurfaces in the two other Abrams movies too. I would still prefer the original character from TOS though. Kelvin McCoy's only remarkable medical accomplishment in his three movies is the coincidental discovery of Khan's miracle blood.
T'Ana (Gillian Vigman) is a Caitian and thereby essentially a cat. She has mood swings and she is headstrong. Most notably, she doesn't seem to have much compassion for her patients and her personnel. That changes a bit in season 2, where we can see that she cares for Tendi, such as in "Where Pleasant Fountains Lie" (when Rutherford is reported dead) and in "First First Contact" (when she recommends the ensign for advanced science training). On the professional side, we get proof of T'Ana's proficiency as soon as in "Second Contact", when she cures the rage virus.
Dr. Pulaski (Diana Muldaur) is notoriously unpopular with fans, and she is not among my personal favorites either. This is mostly because we were disappointed that the very capable but somewhat grumpy woman replaced the charming Dr. Crusher in TNG's season 2. I admit this is a bit sexist, considering that we wouldn't berate McCoy for being occasionally ill-tempered. But it is hard for Pulaski to compete with two fan favorites. And even though she did forge friendships such as with Worf, I just don't like her willful ignorance regarding Data. Her dedication to her job, on the other hand, is indisputable, as seen when she risks her life to cure the rapid aging in "Unnatural Selection".
I needed some time to warm up with Dr. Phlox (John Billingsley). Although he is competent and considerate in everything he does and although he has a genuine kindness, I think he also exhibits a complacent attitude. The Denobulan doctor keeps a distance to the human crew, which is professional but also comes across as cultural segregation. Phlox's perhaps greatest medical achievements are the cures for the infections in ENT: "Strange New World" and "Extinction", as well as for the Klingon augment virus in "Divergence". Well, and he healed himself from Borg nanoprobes in "Regeneration". On the more controversial side, he created the dispensable clone of Trip in "Similitude".
Hugh Culber (Wilson Cruz) is one of the characters of Discovery I can most relate to. He is capable in his profession, with a good balance of passion on one hand and reason on the other hand. I only still can't get over the stupid way Culber was first killed and then resurrected, but that fortunately has no lasting effect on the character and on his relationships.
Julian Subatoi Bashir (Alexander Siddig) started off as a somewhat naïve and awkward young officer in DS9's first season, but grew with his assignments, such as with the Jem'Hadar in "Hippocratic Oath" and the plague in "The Quickening". Only the revelation that young Julian was genetically improved was a somewhat controversial character development from the start and perhaps counterproductive in hindsight, also because this doesn't really seem to be a reason why he is such a good physician.
Voyager's EMH (like probably every other EMH of his design in Starfleet) is programmed with the practically complete medical knowledge of the Federation, including five million surgical procedures. That makes him the most knowledgeable and quite possibly the most skillful medical officer we can think of. Still, there must be a reason why the EMH is activated only in case of an emergency. And although the Doctor (Robert Picardo) has been running for years and has accordingly expanded his program with something that may qualify as empathy, he still could learn a bit about bedside manners. Well, and about loyalty. His derogatory novel Photons Be Free about his crewmates as late as in season 7 (in VOY: "Author, Author") is way out of line.
Leonard H. McCoy (DeForest Kelley) is near the top of my list because of his dedication to his work and his compassion about medical and ethical questions. He may not have been the most pleasant officer to work with, and occasionally spoke up about matters that were none of his business. But as much as they sometimes argued with each other, McCoy, Spock and Kirk ultimately arrived at a solution. If we look at his medical achievements, he found therapies against previously unknown diseases on many occasions such as in "Miri" and "The Deadly Years". He also saved Sarek's life in "Journey to Babel". Well, and he infamously re-integrated Spock's brain in the episode of the same name...
Dr. Crusher (Gates McFadden) is a very capable and versatile medical officer. On the professional side, she develops antidotes and similar therapies on many occasions, such as in "The Naked Now", "Angel One" or "Identity Crisis". She is also engaged in medical research, at one time so much that she leaves the Enterprise and joins Starfleet Medical. Crusher's unrelenting research greatly contributes to the discovery of the ancient message in "The Chase" but also gets her into trouble in "Suspicions". Despite her many professional assignments, Crusher masters her private life as a mother and pursues various hobbies such as theater. Beverly Crusher is amazing without coming across as exaggerated.
I think I haven't seen enough of Dr. Pollard and the La Sirena EMH yet. Nurse Ogawa, unlike Christine Chapel, appeared as Dr. Ogawa only in a parallel reality.