Someone told me once, that programmers tend to learn one scripting language properly and ignore or dislike other scripting languages. Do you have similar experiences?
 I'm using Python as my choice for scripting for  few years, however, I'm sure that there are many existing and emerging languages that could impress the Pythonistas. Can you recommend scripting languages that would be interesting and useful to learn besides of Python?
I'll give an honest answer from my perspective.
No.
Having started scripting using batch, bash, and Perl, discovering Python was discovering precisely what I'd want from a scripting language (and more, but that's off topic). It integrates with familiar Unix interfaces, is modular, doesn't force any particular paradigm, cross platform and under active development. The same can be said of no other scripting language I know of.
The only other scripting languages I'd consider using is Lua or Scheme, for their smaller footprints and suitability for embedding, Python can be a little hefty. However they're hardly suitable for the more general purpose shell and other forms of scripting.
Update0
I just noticed mentions of Ruby and PHP in other answers, these both slipped my mind, because I'd never consider using them. Ruby is slower and not quite as popular, and PHP is more C/Perl like, with flatter interfaces, which comes with performance boons of its own. Using these alternatives to Python is a matter of taste.
Learn a scripting language besides Python