668

Old joke, but it may be old enough that it's fresh for others.

Oddly, the site where I found the original picture, findadeath.com, claims that this was the mailbox for Saint Ronnie himself in the post-presidency years, until the time of his death in June 2004. The site further claims the original address was 666, but Nancy had it changed.

Of course, I can't vouch for either of those claims. I'm just sayin'.