I would argue against some of the schools mentioned above such as JHU. I did not go there, but the committee will not support students who do not meet certain criteria, whereas there are successful applicants at other schools who could get in with a 3.3 GPA and 29 MCAT.
I would rather have a 3.9 from my state university than a 3.4 from JHU, Harvard, Princeton, etc. Based on what one adcom member has told me, you cannot fault the kid with a 3.9 because he has excelled in his environment. For all they know, the student may have been accepted to Princeton undergrad but have chosen the state school due to finances, family, location, etc. In general, the top undergrad schools will be more successful percentage-wise because they recruit stronger HS students...e.g. Emory gets more kids who score 35+ on the MCAT than University of Georgia. So you can't just say schools with the highest acceptance rates are the best. Just as an example, if you look at mdapplicants.com, there are people who have recently been accepted to Harvard Medical School who went to less prestigious schools like East Carolina, Millsaps, Alabama, Xavier, Cal State, etc.
The answer to this question is too individualized to give you a simple answer. For example, personally, I was a pretty strong HS student (top 1% of class, top 1% of standardized tests). I went to a top 20 undergrad. In retrospect, this is what I wish I would have asked schools when trying to decide where to go:
1. What percentage of freshman premeds end up applying?
2. What is the average or median MCAT score and GPA for both accepted students and applicants?
3. Is the premed advising system strong? (At my school, they have given me a lot of great advice)
4. How may students apply each year? (I would prefer schools with 50-350 applicants/year) I went to a school with ~250 applicants/year and even then I thought there was competition for positions such as TA, research assistant, student group leadership, etc. I can't imagine what it would be like at Berkeley or UMich, for example, which have 600+ applicants/year.
5. How many students go into postbac programs or take time off to strengthen their application?
6. Are all applicants supported or are there specific criteria?
If you are a strong HS student, I would argue that a top liberal arts college is one of your best bets. Aside from that, ask the questions I listed above and also consider where you think you would succeed academically and otherwise. There are doctors from hundreds of undergrad institutions across the country. What you do is more important than where you do it.