Perl. A language that is still ahead of its time. I have a system for building RPMs of CPAN modules and their dependencies automatically.
I would like to replace it very much, because I don't like Perl 5's type system very much (and something like Moose is overkill, IMHO, for a 500-line-script).
But it's just so damn useful, and most of the time I can get something to work faster than with Python or Go. So I might not love Perl, but you could say I respect it very much.