I would actually recommend majoring in biology with a course selection heavy on molecular biology.
I majored in biology and did many upper-level electives in microbiology, molecular biology, informatics/genetics, and structural biology (and a med school-esque cardio/pulm/renal course). This made both the MCAT and medical school much easier for me when compared to the experiences of friends who majored in english, religion, etc. Also great practice for analysis of scientific papers, a skill that is very important in medicine. Additionally, nearly all prereqs were also degree requirements at the time. Keep in mind that I did take the old MCAT, and things have changed a bit.
Now, I also did a minor in philosophy, which is enriching in life in general, including in medical school. However, it didn't prepare me at all for actual tested material in medical school, at least not in any obvious way.
Regarding above arguments: all valid considerations. I've assumed you love biology, or at least enjoy science. If you feel that you would rather major in a liberal arts discipline but are thinking about doing bio instead for obvious reasons, go with what you love. If you love/enjoy liberal arts and hard sciences both, go with the science major or double major, or do a minor in a liberal arts field.
And this still all assumes you are certain about going to medical school. If not, I don't think the major you choose will make a difference for job prospects straight out of undergrad unless you do what amounts to a professional degree, such as engineering, which will boost job prospects but may not be worth the effort for someone who will go to medical school unless that plan involves doing biomedical engineering or something related.
But one consideration supersedes all others: If you are certain about medical school, major in whatever will allow you to excel the most as an undergraduate student. Factors that allow people to do that vary from person to person, but a love for the material isn't essential when you begin. I didn't choose biology at first (freshman year, I guess) because I loved it--rather, it was for practical reasons initially. I came to love it later.