Personally, I'm very careful who I tip though, depending on what country I'm in.... In HK and China, I've actually had a couple of offended waiters return tips, where they explained good service should have been provided anyway, and no tip was necessary.
It seems to be a cultural thing, and sometimes I've been given the feeling that it was offensive to suggest that good service was provided only in the expectation of a tip. Having said that, I do round up to the nearest on things such as taxi fares etc.