Valleygal, I agree with you. Research is definitely a big "must-do" for (some of)the top 10 medical schools. I'm sorry that you had such a disappointing experience, when it is evident that you are a very qualified candidate.
Another VERY big factor, however, is choosing the schools you apply to because of YOUR fit for the school's educational philosophy. Many of the top 10 are heavy on applicants doing research because that is what they value in a physician--"physician scientists."
I did two years of research in undergrad, but none of it was "stellar." Let me just say I learned how UNFIT I am for a career in research science, and my research recommendation letter was not exactly brimming with exuberance. However, I did quite a lot of work in the humanities--specifically, writing and studio art--and I incorporated these into working with the elderly (because I really enjoyed it, not because it would look good on an application).
I applied to 4 top 10 schools. What I discovered during applications was that:
1) Schools heavy in didactic teaching and research rejected me flat out. Part of this was, I think, due to coming from a non-ivy undergrad (if I remember correctly, doesn't Yale's secondary ask if you have any family members that ever went there? ridiculous!). But it was also due, I think, to my lack of publication after two years of research.
2) Schools with a heavy emphasis on self-directed learning and the integration of arts and sciences were enthusiastic about my art and writing. I got one top ten acceptance within a week of interviewing, and another waitlist soon thereafter. As I was a non-Ivy undergrad, I was actually really surprised at the acceptaces.
3) The schools _I_ really liked were the ones that accepted me. And the one I finally chose to attend (because the learning environment suited me) has been a good fit.
Really, there are no significant differences in quality of education between any of the top 15-20 schools. There are, however, large differences in educational philosophy, and this can have a tremendous impact on your acceptance to a school.