Only get a plate that's hard to remember if you plan to run from the police.
If you're basically law abiding, consider one that might influence the police officer to let you off with a warning. I'm pretty sure that my GRAMMPA plate has helped me get a few warnings when stopped. I haven't gotten any tickets since I got that plate - except for one while driving my wife's car in what I consider to be a zero-tolerance sting operation.
If you can't come up with something that you feel is the obvious one to get, don't bother getting one.
The plate for my Honda was the obvious choice.
