One of my former bosses had a system for milk:
1) Smell it. If it smells OK, drink it.
2) If it smells funny, pour it into another container and smell it again. If it smells OK, drink it.
3) If it smells funny in the new container, taste it. If it tastes OK, drink it. Only if it tastes yucky should you throw it out.
I know a mom who is one of those who thinks expiration dates are on packages because they are required to put them on there, not because the food could actually go bad. ICK! She will cook something, let it sit in the fridge for 7-10 days, then freeze it. She will then take those frozen portions out once in awhile and fix them for dinner.

Her MIL told me she stopped taking leftovers when this lady offered them because the stuff made her sick half the time! Well, yeah, 10 day old meatloaf will do that.
I'll go 2-3 days past the expiration date on some things, otherwise it goes in the trash!