AJ Troxell

With the Custom Login Page, you can change the background image of your login page, the background image/colo of your login form div, the main logo image of your login page, and add custom CSS. 
All through a simple interface. Remember to view the Help tab at the top of the settings page for the plugin.

Custom Login Page

Wordpress Custom Login Page allows you to change the background image, logo, form div attributes, and custom css of you Wordpress login page.

itzoovim

WordPress Login Box (WPLB) lets you add a log in/out box to your website.
WPLB includes an options panel which gives you control over your form.
Features:
<ul>
<li>Different styles</li>
<li>Highly customizable</li>
<li>Lightweight</li>
<li>Can be integreated with any theme</li>
<li>Works well with other plugins</li>
<li>Hackable</li>
</ul>
This plugin lets you choose custom links for a forgot your password page,and registration page. 
It also lets you choose a url that you users will be redirected to after they log-in/out. 
You can also enable the option to not redirect your users to WP-Login after failed login attempts! 
This plugins works well with other member plugins, and can help you create an overall better user experience.
You can view a sample <a href="http://itzoovim.com/plugins/customize-and-add-a-wordpress-login-form-to-your-site/#sample_wordpres_login_form" rel="nofollow ugc">wordpress login form</a> by visiting this link.
<h3>Requirements</h3>
In order to work, WPLB needs the following :
<ol>
<li>PHP version 5+</li>
<li>Preferably the latest version of WordPress.</li>
</ol>
<h3>Donations</h3>
We are still working on a donations link at the moment. For now, leaving a nice rating will be appreciated as well.

WP Login Box

Easily add a forum like log in/out form to your site.

Custom Login Page vs WP Login Box