There was an editorial in the Chicago Tribune (or maybe a letter to the editor) about a Chicago teacher who retired with 325 unused sick days. In Illinois, by law you get paid for accrued but unused sick time. That's like an extra 11 months pay.

I've rarely taken my entire two weeks because of my cat, and because of having to arrange for coverage at the different places I've worked when I worked in the hospital I was hourly and the time accrued faster, so I did take it. I used up a lot of vacation days when I was in grad school, too.