GitHub, because everyone uses it and because the developers haven't ever accidentally deleted the production database.
Seems that Github also destroyed a database.
Accidents happen. Both companies seems to be open about their issues and are willing to improve. I do not hold it against them.
It could in fact result in a a more stable service, as the developers will start thinking about all the other stuff that may happen.
As qw mentioned, we know of at least one time this happened to Github.