I've been using IntelliJ products for over 10 years now, and I've been a massive fan of loads of different plugins. The past two years I've moved primarily to Front-End engineering and I've adopted Webstorm as my current go-to editor.
Here's a list of the plugins I'm currently using:
1. Material Theme UI
3. Rainbow brackets
4. Indent Rainbow
5. .env files support
6. Styled Components & Styled JSX
9. PlantUML integration