For test data I like to use different movie or comic book names for different epics.

So when we start a new epic with multiple user stories I decide this will be all star wars, or matrix or donald duck characters, etc etc. The nice thing about it is when certain test data gives unexpected errors in other parts of application its easy to track where the test data is from.

I once made test users who were all named John Smith in different languages. I learned that basically every name is a variant of John.