Drupal WYSIWYG editor : HTMLArea

Installation

Fairly simple. Drop in the module and enable it. Download the Xihna javascript file and place it into the xihna folder within htmlarea module folder.

Configuration

There's a lot of settings so I can see how configuration could feel confusing or overwhelming. Luckily, once you click through the options it becomes more clear as to what all these configuration settings do. Many of the options are checkboxes that will add or remove buttons from the toolbar or enable or disable plugins for the editor.

Three other configuration pages will allow the administrator to determine what font sizes and styles are available.

As with most other modules you can have the WYSIWYG only be displayed on specific forms by limiting the url paths.

Usability

From a user standpoint this WYSIWYG editor is as simple as using a word processor. As long that every single plugin and toolbar option isn't enabled the interface is clean clear and self explanitory.

Clean Output

From what I have seen thus far the markup is very clean. It has an option to use XHTML instead of old school HTML which still uses degregated tags.

Handles Images

Without a plugin you can reference images by providing the image url. There's an ability to override the image size, but the image is only being rendered in the new dimensions not actually resized and stored.
However, the Image Management plugin is incredible. It's able to create new directories to organize images. It allows you to perform simple task like crop, rotate and scale images as well as align and put borders around them.

This plugin requires that Image module is installed, but once that's in place and the plugin is enabled it's very simple and powerful to use.

Works w/ Asset Module

No, but with the plugins I have found it just as capable as the first version of asset module, if not more powerful.

Cool Features

All the plugins that are available once you drop in the Xhina files.

Plugins

There are tons of them. But I'll point out a few interesting ones.
ImageManager
Find & Replace
Super Clean
Spell Checker