VS Code has very poor LaTeX support out-of-the-box. Here I list useful extensions and other software that will transform VS Code into a much more power LaTeX editor. They also do not conflict with each other, which is great.
Getting it out of the way: LaTeX Workshop
While I have used LaTeX Workshop for a long time, I started experiencing a few issues with it that, over time, got really annoying. The main issue is simply the Enter key not working, which was then replaced by a substantial delay between pressing the Enter key and actually inserting a new line character. Fixing one apparently introduced the other, so, after many tries, I just gave up on LaTeX Workshop.
What I use now
- Syntax highlighting Rich LaTeX syntax highlighting (for use with Texlab)
- Grammar checking: LanguageTool for Visual Studio Code + one of the multiple language support extensions + LTeX for LaTeX/Markdown support
- Code completion and other shenanigans: TeXLab + its VS Code extension
- PDF visualization: Open to open a file in its default application. While there are extensions that explicitly give VS Code the capabilities of opening PDF files with PDF.js, I find PDF.js too simple and prefer just using Acrobat or Okular.