Top Rated for IntelliJ IDEA Community Edition

RegexpTester

Regular Expression Tester for IntelliJ IDEA.

Autoscroll Save

At last, a handy way to save your Autoscroll to/from Source settings :).

Elm language plugin

Plugin for Elm language support.

Key promoter

Shows to user how easy he can make same action using only keyboard(menus and toolbar button mouse clicks initiates shortcut display).

SQLScout (SQLite Support)

First-class SQLite support for Android Studio and IntelliJ IDEA.

VisualVM Launcher

Launches VisualVM from within IDEA.

Gerrit

Gerrit Code Review Tool Integration Only Gerrit 2.6 or newer is supported (missing / incomplete REST API in older versions) ...

Latte

Provides support for Latte – a template engine for PHP.

LivePlugin

This is a plugin for IntelliJ IDEs to write plugins at runtime without having to restart IDE.

Zero Width Characters locator

Inspired by this question on Stack Overflow - this plugin adds an inspection that prevents some hard to find bugs related to invisible zero width characters in source...