Would you want someone to tell you if you had bad breath?

Probably. If no one pointed it out I'd never know otherwise (in this scenario where I wouldn't know at least).

Of course there are nice and meaner ways of putting it, but I'd at least appreciate someone pointing out something offensive about me so I could re-evaluate/consider it/realize it (or in this case maybe use mouthwash or something).

if there's a snot or a booger i have no problem, bad breath im more afraid to say something to be offensive

Yes, I'd appreciate it and make corrections

Yep, the missus does it regularly. I do the same (add telling her she has ‘crazy hair’ to the list).

I was arrested on Thursday morning and one of the policemen had terrible breath. I could smell it from 8ft away. I thought better of saying anything. P.S I was released later that day without charge.

always carry some mints.