Top Rated for IntelliJ IDEA

Grammar-Kit

BNF Grammars and JFlex lexers editor.

JavaDoc

Plugin that generates java docs on java class elements, like field, method, etc.

Phalcon auto-complete

Provides autocompletions for Phalcon framework.

Crater

Adds option for a JSONObject and Cursor constructor.

Go

This plugin extends IntelliJ platform with Go-specific coding assistance and tool integrations, and has everything you could find in GoLand.

Quick Notes

Quick Notes is a plugin written for IntelliJ IDEA.

ADB Idea

Adds the following ADB commands to Android Studio and Intellij:.

Tab Shifter

By syl
This is a plugin with a bunch of actions to move tabs between editor splits and resize splits. Actions are added to "Main Menu -> Window -> Tab Shifter".

Erlang

Erlang support for IntelliJ IDEA, RubyMine, WebStorm, etc.

Script Monkey

Script Monkey breaks the boundaries of Java and helps Java achieve the power & flexibilities of interpreted/dynamic languages.