Broken sector

I seem to have bad karma when it comes to harddrives. The upside is that I've become very paranoid about having proper backups on all my data. Last week, just before leaving town for a week, my primary harddrive on my new computer started getting bad sectors. Running chkdsk seems to have fixed the problem, though. But I'm wondering what I'm doing wrong. I've got a stack of three harddrives standing on my desk in various stages of brokenness.