I use VScode a lot, it has been default for me from last 3 years. Here's a list of the best extensions and themes which I came to know about.

Also let me know those which you use down in the Comments :)

Cheers !

Here it goes ...

Live Server

By: Ritwick Dey

Downloads: 3,821,711

Life saver !
With hot reload and multiple port support it is a must have for every dev out there

REST Client

By: Huachao Mao

Downloads: 743,203

Alternative to POSTMAN OR INSOMNIA.

REST Client allows you to send HTTP request and view the response in Visual Studio Code directly.

Bracket Pair Colorizer 2

By: CoenraadS

Downloads: 567,560

I love this extension, it allows matching brackets to be identified with colours.

Auto Close Tag

By: Jun Han

Downloads: 2,322,183

Automatically add HTML/XML close tag, same as Visual Studio IDE or Sublime Text does.

Auto Rename Tag

By: Jun Han

Downloads: 2,253,172

I came to know about this recently, It Automatically renames paired HTML/XML tag, same as Visual Studio IDE does.

Color Highlight

By: Sergii Naumov

Downloads: 733,566

This extension styles css/web colors found in your document. It supported every document type which I have worked with.

Color Picker

By: asneki

Downloads: 435,799

Best one ever !
It has a GUI to generate color codes such as CSS color notations

IntelliSense for CSS class names in HTML

By: Zignd

Downloads: 1,889,857

It provides CSS class name completion for the HTML class attribute based on the definitions found in your workspace or external files referenced through the link element.

Path Intellisense

By: Christian Kohler

Downloads: 2,467,503

This VSCode plugin autocompletes filepaths and filenames.

Rainbow CSV

By: mechatroner

Downloads: 460,612

• Separated files in different colors
• Provide info about column on hover
• Multi-cursor column edit

AND MUCH MORE

Prettier - Code formatter

By: Esben Petersen

Downloads: 4,860,985

Prettier is an opinionated code formatter. It enforces a consistent style by parsing your code and re-printing it with its own rules that take the maximum line length into account, wrapping code when necessary.

Excel Viewer

By: Grapecity

Downloads: 713,497

This extension provides read-only viewers for CSV files and Excel spreadsheets within the current Visual Studio Code workspace.

Data Preview

By: Random Fractals Inc

Downloads: 34,914

Data Preview 🈸 extension for importing 📤 viewing 🔎 slicing 🔪 dicing 🎲 charting 📊 & exporting 📥 large .json array .arrow .avro data files, .config .env .properties .ini .yml configurations files, .csv/.tsv & .xlsx/.xlsb Excel files and .md markdown tables with Perspective - streaming data analytics WebAssembly library.

NOW HERE ARE THE THEMES FOR YOU GUYS

1. Linux Themes for Visual Studio Code
2. Gruvbox Themes
3. Monokai
4. Monokai Dimmed
5. Shades of Purple Theme for VS Code
6. Palenight Theme
7. Calamity Theme for VSCode
8. Arch theme
9. Material Theme
10. Atom One Dark Theme
11. Cobalt2 Theme Official
12. Vue Theme
13. Firefox theme
14. Popping and Locking (My Fav)
15. Dracula Official
16. Dank Neon