refurb
This is my perspective as a Tuck student, but I would put stats and accounting at the top of the list. Those are two courses that people often have trouble with. You can get by not knowing a ton of calculus (at least for the first year).
If you were to take accounting and stats and really nail it (A- or A), you'll go a long way to convincing admissions that you'll do just fine with the course load. Plus, you'll feel a lot more comfortable in first year classes.
RF
I definitely want to take intro calculus because i haven't taken it since high school, and i come from a humanities background, so the admissions committee will be wondering about my quantitative skills.
I was debating between business stat and accounting but chose the former since stat is very important to doing well in a rigorous MBA curriculum. If I didn't have to study for my GMAT, i would take accounting as a 3rd course, but that's just not realistic.