What kind of food intolerances does everyone have?

I'm lucky enough not to have any but my girlfriend can not have any dairy otherwise she is violently sick. Seriously, she had a few licks of a creme egg a couple of years back and ended up in hospital. I'll be sure to steer clear of the chocolates come Valentines Day. Plus, cooking for her is an absolute nightmare as you have to check every ingredient to make sure there are no traces of milk.

So... what can't you eat?