Mimelim's guide to picking the best medical school
Let us get somethings out of the way first. You can take these as fact:
#1 There is no one best medical school.
#2 There are better schools than others.
#3 Every applicant has different wants/needs and what is best for you may not be the best for other people.
#4 For every applicant, there may be one 'best' school, but there are dozens of schools that they would do well at.
#5 No matter how much time and energy you put into this, you will be naive and never get a 'perfect' answer. And that is okay!
Your only goal is to find the best medical school for you. The secret to this is that nobody, not your pre-med advisers, your friends, your family, faculty nor SDN can tell you the answer to this. The primary reason for this is that everyone is private about certain things. You don't share all your wants/desires/goals with the entire world. There are things that matter to us that we don't necessarily want the world to know. Also, the vast majority of things are continuous variables and are incredibly difficult to fully communicate to other people to help them do the computation with/for you. To solve this question, first you need to define the variables. The following are the major variables in no particular order.
a) Academics
b) Finances
c) Proximity to family
d) Proximity to significant other
e) Research opportunities
f) Clinical opportunities
Do not underestimate the importance of all of these. I will skip academics until the end since that is the easiest to see the need for, but hardest to really integrate.
Finances - Medical school is expensive. You can google for your own stats of the week. It is not uncommon for people to have 200k+ in debt. You will be working as a resident/fellow for 45-60k per year for somewhere between 3-9 years after you graduate. You will likely be in or closing in on your 30s at that point. That is a big hole to start one's career off in. As a physician in the US, you will not starve. You will be comfortable. You will make more than the vast vast majority of Americans. But, good financial prudence EARLY goes a long way. Never mind specific goals. Being financially savvy early will give you flexibility later.
Proximity to family/SO - Medical school is hard. The biggest problem is that it isn't just academically hard. It is hard from a personal standpoint. You will be working hard, all the time. This takes a toll on relationships. But, more than that, people do better when they have a strong support system. You don't HAVE to have people around. But, you will be a better doctor if you are happy. Part of that, for most people, is being around the people that they love.
Research/clinical opportunities - You can go into any specialty from any medical school. Yes, you can. But, realize that it IS harder coming from different schools. Part of it is prestige. However, I would argue far more importantly, it is about opportunities. You can't do ENT research if there is a tiny ENT research presence at your medical school. You can't work with XYZ if you don't go to the medical school that they are at. Do not get me wrong. A far bigger issue these days is medical students squandering opportunities, rather than them not existing. But, be aware that if you are looking to go to a competitive specialty or a competitive program in a less competitive specialty, you want as many opportunities as you can get.
Academics - *deep breath* - You are who you are. Where you go to school will have little impact on your board scores. Yes, your pre-clinical curriculum matters, but if you are a good student, you will do well on your boards regardless of where you go. You may need to structure your own study time a little better, cover things that weren't covered as well at your school etc. But, for the most part, your board scores are reflective of YOU as a student, NOT your school. What is on the tests is no secret. The kinds of questions they ask are not a secret. There are quite literally, thousands of high quality practice problems out there. There are two things that matter more. Clinical exposure and the quality of co-students. Your clinical education is INCREDIBLY important and as most medical students will tell you, highly variable even within a single institution. To get an idea of the quality of clinical curriculum, you have to talk to students, as many as you can. And in the end, you will NOT have a perfect picture. Nobody can encapsulate all the experiences at a given school. I think one of the hardest things to figure out with medical students is who is happy because their rotation is light and who is happy because they are in a position to learn a ton. Which leads into the other important aspect of academics: Who are your classmates? You will learn from your classmates. Not just academically, but about any number of other things inside and outside of the hospital. Being around serious students is important as much as I don't like sheep, it is a lot easier to work your ass off constantly if everyone around you is also doing it. This is the only thing that those 'rankings' give some idea of. Higher average GPA/MCAT means higher academic prowess, nothing more, nothing less.
If you take away nothing else from this, remember, this is incomplete. I implore you, use those rankings as a list of schools to look into, nothing more. Do your research. Talk to people actually at those schools, or look at the school threads here on SDN. And, think about other things besides academics when ranking things for yourself.