My favorite language is BLISS, but that's not a language for people who like complicated, difficult to master languages like C, C++, etc....
Fortran may be the most important language today; a very simple language which wasn't designed to be extended so the extensions came a cost.
FORTH is another simple language that is very powerful due to its builtin bootstrap nature.
G-code, aka RS-274, is a trip back three decades - only someone who have at least a few decades in the computer industry can truely appreciate its stunted development.
I haven't really thought about it for a quite some years, but I wonder if someone has updated Jean Sammett's computer language family tree.
It seems to me that the industry has stopped exploring the nature of computer languages, problems with and using programming languages, and all the interesting computer language discussions of the 60s and 70s...