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

Plugin homepage
2. CodeGlance

Plugin homepage
3. Rainbow brackets

Plugin homepage
4. Indent Rainbow

Plugin homepage
5. .env files support

Plugin homepage
6. Styled Components & Styled JSX

Plugin homepage
7. Kubernetes

Plugin homepage
8. Swagger

Plugin homepage
9. PlantUML integration

Plugin homepage
10. Zero Width Characters locater 2
Plugin homepage
11. Main Menu Toggler
Plugin homepage