If you too had written a compiler you would know what I'm talking about.

"Commonly Used" and "Good" are completely unrelated. Now, Objective-C preceeded it and is what C++ should have been, but it's not needed today either.

Either way, what is the coolest blood line limit so far? Haku's is a good bet, but maybe the 1:st had a limit as well because the "Birth of the Trees"-jutsu could only be used by him, and if it is then I vote that one ;-)
(with "Birth of the Trees" being my favorite jutsu so far)