What's the largest tax refund you have received?

This year we had a very unusual year, our income was about half what it has been for several years now, I was self employed, and received wages as an employee, my husband was laid off, but received some severance, we bought a business, and we moved.

I had no feel for whether I would owe taxes, or get money back, for 2016. Turns out I am getting the largest return I ever have (assuming everything is done right).

It got me wondering the largest return other people have received, and did it make you wonder if something was done wrong? I just read over some rules about IRA deductions double checking my accountant. Making myself crazy as usual.