Wreaths seem to be the most common front door decoration. When I saw this sign (found at Target), I wanted to put it on the front door, though. Not inside the front door -- on the outside.
(Also, the tone of the colors matched the tone of the paint on the outside of the door very nicely.)
I think a sign on the front door gives guests a better idea of who lives inside. And some, like this sign, can be a positive reminder to anyone. This sign is a good reminder for me every time I leave or return!
Do you like front door signs?