A thread at WebmasterWorld named My Best Click Ever asks people to list the highest paid out click, they received ever. Firstly, to get the numbers of a specific click is almost impossible in AdSense. The only way to really get an accurate count is to have one impression and one click. Otherwise, your revenue for a channel can be inflated through CPM revenue. And if CPM is taken out of the equation then if you have more then one click, you can't calculate the single value of each click, you can get the average.
Having said that, here are some of the numbers reported at the thread.
Just remember, here are two quotes from the thread.
Google does not update channels simultaneously and sometimes has random "click dumps" which may appear like you earn more in one day, but infact its the same amount with just a click dump from an earlier time.
The CPM for this particlar channel was something in the tens of thousands. To be honest with you I don't know what to think about it, I suppose it could have been revenue carried over, but its odd that the clicks/impressions weren't also carried over. Plus it happened in a rather obscure channel.