IntelliJ IDEA is a powerful and feature-rich Integrated Development Environment (IDE) that offers a wide range of productivity-enhancing plugins. Here are some of the best plugins to improve productivity in IntelliJ:

1. Key Promoter X: This plugin helps you learn keyboard shortcuts by displaying pop-up notifications whenever you use the mouse to perform an action that has a keyboard shortcut.

2. IdeaVim: This plugin adds Vim keybindings to IntelliJ IDEA, allowing you to use your favorite Vim commands and shortcuts within the IDE.

3. Rainbow Brackets: This plugin highlights matching brackets with different colors, making it easier to identify nested blocks of code.

4. SonarLint: This plugin performs a static code analysis to detect potential bugs and vulnerabilities in your code, providing you with suggestions to fix them.

5. CodeGlance: This plugin adds a code minimap to the editor, allowing you to easily navigate through your code.

6. AiXcoder Code Completer: This plugin provides intelligent code completion and helps you write code faster by suggesting relevant code snippets based on your context.

7. Code Time: This plugin tracks the amount of time you spend coding and provides insights into your coding habits, such as which languages and frameworks you use the most.