The great thing about medical dramas is they make you feel like a doctor without having to do any of the work. Even when the characters are involved in impossibly convoluted love quadrangles, facing lawsuits and any other number of complications, you still feel a little bit like it would be great to be a doctor. This is of course unless you're an actual doctor, in which case I'm sure you see it a little differently.
The great difficulty with any of these dramas is blending the medical facts and procedures/surgeries with human drama. The medical side is what gives it a niche, and gives a sense of action and excitement, but the human drama and the characters are what keep you hooked.
5.Grey's Anatomy
This is incredibly girly and sappy, and the focus is more on soapy story lines than on the medicine, but there's a decent cast and they interact well. This one's mainly for girls and people who like dramas where everyone's sleeping with everyone. In fact its a bit like a medical version of One Tree Hill
4.Chicago Hope
This one is a bit old school but its actually better for it. There's humour drama, but its not as pulpy as Greys. It was fairly edgy in its time, with swearing and nudity managing to sneak in past the network moderators. Its also interesting to see Peter Berg in his breakout role
3.Bodies
Most British medical dramas are in the same category as Casulty and Holby City, pedestrian and somewhat mundane. If this is the rule for British medical drama, then Bodies is the clear exception. Dark, bleak and painting a damning portrait of the NHS, and of surgical incompetence
2.ER
15 seasons..that alone says more about it than anything else. A drama that had equal focus on the characters and the medicine, and balanced it beautifully. Often plots spanned several episodes, never letting sappy melodrama overshadow medicine and the realistic portrayal of what doctors end up having to go through. The cast may have gotten a bit choppy by the end, but it stayed a quality product right to the end
1.House M.D
It was hard deciding between ER and House since both are excellent, but in the end this had to take it. Hugh Laurie's performance is a masterclass and binds the whole show together. High in suspense, deliciously Machiavellian and devious, it was also frequently, savagely funny. I think what makes House win out over the others is how well it reinvents the medical drama, turning it into a medical detective show with a humorous, near psychopathic protagonist
