I really have no desire to chime in on this but the number of misinformed posts on this thread is silly. I am matriculating there in about a month so feel free to pull the bias card but here's my attempt at objectivity, in no order.
-Endowment. It's enormous, and they're happy to finance summer research, extracurricular projects, AND...
-Financial Aid. Their endowment allows the financial aid office to offer an initiative in which anyone who has parents earning <120,000 has a $0 expected parental contribution, and for the most part this just means a $24,500 unit loan per year, amounting to around $100,000 after four years. No merit aid, so if your parents are wealthy, the financial aid will be a bit more skimpy but last I heard this covered >50% of matriculating students.
-The students. They're inspected during the application process for leadership traits, ambition, motivation, intelligence and creativity (and hopefully this is not just my wishful thinking, this is stated by the admissions office, and reflected by the fact that we are not the highest stats school in terms of GPA and MCAT). What does this mean? I'm hoping it means that we have a high concentration of the future leaders of healthcare, whether it be Med-school deans, company CEO's, or public policy figures. I'm certainly looking forward to knowing and working with these people...
-The clinical experience is incredible. Where else do you have several (B&W, Children's, Beth Israel, MGH) world-class hospitals. Nowhere.
- Research. Sure, you can say there are just too many faculty and students get lost or don't get many real responsibilities. I'm not a student yet so I may be wrong, but those I've spoken to say emails reaching out to a particular faculty member or doctor have been received exceptionally well and never have problems coordinating a meeting or lab experience. Not to mention, the sheer volume and quality of research means there's a good probability of not just finding a lab studying the absurdly rare thing you're interested in but also that your ground breaking research will be all over the news one day. Seriously, how many times have you heard or read: "Today, researchers at Harvard Medical School..."
-Dual-Degree opportunities. While an MD may ultimately be an MD, an HBS MBA is not just another MBA and a MPH from the School of Public Health is not just another MPH. The curriculum is structured to make fitting in a second degree easy, and it is very much a name game when it comes to these opportunities for students interested in health policy or administration.
-The girls. It's pretty fun telling a girl you just met that you're an incoming HMS student. Ok I'm kidding, but it sures does work magic in convincing your girlfriend's parents who have hated you forever that you're a worthy mate for their precious daughter.
There are several more reasons; Boston is a great city for people in their 20's (yeah the weather sucks), possible benefits in securing prized residency positions, and the opportunity to be in the midst of medical academia for your entire career, just to name a few.
Lastly, yeah there is a bit of snoodiness but that really wears off very quickly. I go to HMS, I'm hoping to love it there, I think it's the ideal medical school for ME, and I'm proud of that fact. Does it make me think I'm better than any other med student? No. The application process is a crapshoot and I often feel guilty for taking a spot from someone out there perhaps reading this who is much smarter and more hardworking than I will ever be. In the end though, only about 30-50 people a year turn Harvard down, and three of the four I know this year went MD-PhD elsewhere after only getting in MD at HMS. Ultimately, it's a great opportunity with few downsides for most people.