Examiner? You mean professor?
You should get LOR's from:
-Professors, definitely. The better you know them (and the better you did in their class), the better. Schools often require 2-3 of these.
-PI's or preceptors or postdocs supervising your research. Research is a big thing for medical schools.
-Supervisors if you worked in a clinical/research job. Clinical experience is also a big thing.
-Program directors of a big project you worked on. Volunteer/social/leadership experiences are good to have.
The more enthusiastic and personal a LOR can be, the better. Of course, make sure they are all positive.