I really like Is for the simplicity at the time of check data types. Usually this can replace all validation libraries in my projects.

I really like

• React because it's great for the frontend
• Underscore.js because it saves much time and is efficient
• dotenv for hiding your personal stuff
• passport.js because it not only provides a great starter kit for authentication, but also to actually learn about authentication ;)

Lodash is my favourite too and I use it a lot more than the other libraries. My second favourite library has to be node-ssh.

How does it help you? Well, sometimes you need to programatically SSH onto remote machines and execute commands. I think it's a pretty cool library to use.