Well, the First Aid and the Alien Abduction ads are new...
I saw them when I first found the site, about a year ago, I think.
I still think that the abduction one is the funniest.
The monkey was like 'I know how to handle this'.
The theft recovery is also great, as is the egging one. Following it up is the chaperon one(for the shotgun racking alone!) and the road rage one.