Here are 10 of the best Visual Studio Code extensions for Flutter developers:

1. Flutter: The official Flutter extension for VS Code, which provides tools for debugging, code completion, and more.

2. Dart: Provides support for the Dart programming language, which is used for Flutter development.

3. Awesome Flutter Snippets: Offers a collection of Flutter snippets to speed up development.

4. Flutter Intl: This makes it easy to manage localized resources in your Flutter app.

5. Flutter Outline: Provides a tree view of your Flutter widget hierarchy for easy navigation.

6. Dart Data Class Generator: Generates boilerplate code for data classes, saving time and reducing errors.

7. Flutter Staggered Animations: This helps create beautiful animations in your Flutter app with minimal effort.

8. Flutter Files: Generates new Flutter files and folders with a few clicks, reducing the need for manual file creation.

9. Flutter Color Picker: Provides a color picker for Flutter apps, making it easy to choose and apply colors.

10. Pubspec Assist: Helps manage your app's dependencies in the pubspec.yaml file, making it easier to add new packages and libraries to your project.

These extensions can help streamline your Flutter development workflow, making it easier to write code, debug, and create beautiful, functional Flutter apps.