I wish my SSN was 123-45-6789 January 18, 2006
Because I'd be famous to programmers everywhere! SSN of course is Social Security Number. Whenever we programmers write a program that takes an SSN for input, the most highly used test data for the field would have to be "123-45-6789". Just because the counting style of the number lets you know when to stop. "Stop at 9", I always say to myself. Whereas if you were to put in "111-11-11111", you might enter too many numbers (as I just did, which, of course, is a good test of your software).
Similarly if you live at "123 Main Street, Anytown USA". Your address, probably only second to Santa Clause's, is one of the most written in the world :) Of course, this is all speculation.
But out of those two examples, there has to be someone with the SSN of "123-45-6789". There'd have to be! Well, no there wouldn't. That sequence of numbers allows for 1 Billion permutations (10^9), and there's *only* ~280 Million in the SSN using world. I hope in my next life I get that SSN.