I haven't seen a lot of ER, but GA is a fundamentally different type of show than House or Scrubs. All three programmes, as TV shows, have as their main goal the entertainment the viewer. How they attempt to achieve that is very different. House is at its core a mystery/detective show, with Dr. House being a medical stand-in for Sherlock Holmes. House has more in common with CSI than other medical shows like GA. Its suspense comes from House and his team coming ever-closer to solving the case-of-the-week. Fans of the show would say compared to GA, this type of "medical-mystery" show actually works the brain, and ties in many real-life diseases. Unfortunately, one unavoidable side effect of this show format is that every single episode is necessarily a Zebra (a rare, obscure disease), and with time this stretches plausibility.
Scrubs is a sitcom whose first priority is to make you laugh. The second priority is to throw in some clever, pointed observation about life as a doctor. It tries to be a medical show not by showing you different diseases (as in House), but instead by showing general issues faced by doctors (death, legal liability, etc). A lot of SDNers swear by Scrubs and claim that due to this aspect, it is "the most realistic medical show" out there. In my personal experience though, those "medical-life" tibits are far and few, tend require a considerable leeway of interpretation, and are often drowned out by a lot of whimsical (albeit hilarious) slapstick comedy.
GA's first priority is neither to weave a medical mystery, nor to be funny (though it often is). Although GA is by far my favourite of the 3 shows, I admit it is the one with the
least amount to do with medicine. Thus, to be honest, a
pre-med forum may actually not be the best place to be looking for input about the show. The show is exceedingly, addictively entertaining, but probably has more in common with
Desperate Housewives than the other 2 shows. GA is an old-fashioned,
high-concept character-drama, also known as the prime-time Soap Opera, of the same lineage as Melrose Place.
The story revolves about the life and loves of its characters, instead of revolving around the disease-of-the-week, or even medical life. The medical profession provides a convenient background/"world" for the characters to inhabit. However, this particular backdrop is carefully chosen and fully exploited. In soap operas, most of the entertainment is created from tension; without tension there is nothing to watch. Tension is created not by medical mysteries, but by character interactions. Most of the tension is necessarily romanto-sexual. However, the stress-tension of surgical internship, as well as the "class-conflict" tension of the hierarchichal hospital system (attendings > residents > our interns) is harnessed to create a more complex, richly-layered kind of tension.
In addition, I think what made GA a success is its well-defined and generally identifiable/loveable characters. I personally found the George O'Malley character to be one of the most personally identifiable TV characters ever. The cast of characters, their personalities, and histories were carefully designed and set up like prepared chess pieces to allow maximum "degrees of freedom" in possible, potentially entertaining story arcs. Case-in-point; Many viewers (mostly females) are currently enjoying the push-and-pull tension between Meredith and Derek. At the same time, there lies beneath the surface the possibility of a George/Meredith relationship. What is especially clever of the writers is that George was set up as having a huge crush on Meredith right from the very beginning; this facet of his character was kept on the back burner, but never eliminated, even though it was not being currently "worked on" via any of the open story arcs. It's just something simmering in the back, in the writers' tool set. It would have been far less entertaining if, in some future episode, George were to develop and consumate a crush on Meredith
de novo. Instead this is something that's hard-wired into his very character, despite the writers deliberately not calling excess attention to it.
Okay I'm too tired to form any form of coherent conclusion from my ramblings. Hope you enjoyed.
😛