"Son Of A Gun"
– Handprinted Silkscren Print –
There are a couple of interesting etymological theories on the expression.
For example the one where Apollo 12 Astronaut Pete Conrad, upon touching down on the moon, said: "Hey, there it is! There it is! Son of a gun, right down the middle of the road!"
Let's simply keep it with "You son of a gun, you did it!"