I love BASH, with moderate knowledge of it you can do so much with ease.
I especially like using its arrays and rematch regex for quick utilities where reaching for Python or PERL otherwise just doesn’t seem worth the time or potential loss of portability.
Most recently I wrote a a script to scrape a visualisation graph from an external webpage, refreshing its view every 10minutes but only between core business hours, and sleeping precisely until the next day when outside those hours, displaying it directly in the terminal with iTerms imgcat 
But my most valuable and oft used script is one I wrote to update my DDNS IP address in Cloudflare.