When filling out a W4, what is the best option for someone who is married, and both spouses work, they own a home, and pay student loans.

There isn’t necessarily a “best” option. Claiming exempt means they will not take any taxes out at the end of the year (you only quality for this if you had all your taxes returned the prior year).

By claiming 0 allowances, the max amount will be withdrawn from your paycheck, and each allowance you claim over that will add to your take home pay. The less allowances you claim the more they take our of your check.

Click this link from Turbo Tax to get a better understanding.