Asvin Balloo

This plugin will add a “Back to top” icon automatically to your blog. It features a smooth scrolling effect and customizable options such as the color, position and scroll duration, sprinkled with some cool CSS3 effect.
By <a href="http://htmlblog.net/" rel="nofollow ugc">Asvin Balloo</a>.
Supported features:
<ul>
<li>Smooth scrolling animation</li>
<li>Customizable options via the admin panel</li>
<li>Works on almost all browsers</li>
<li>No need to add any markup to your theme</li>
</ul>

WP To Top

This plugin will add a "back to top/ scroll to top" icon automatically to your blog.

Chandan Garg

Are you looking for easy and best wordpress plugin to navigate top of your webpage with great animations ? 
CG Scroll To Top provides a way to customize your webpage scroll down pointing with colours and dial size. It provides a custom setting page in wordpress admin which is very simple. So, you can easily customize your scroller information part easily.
<h4>More Information</h4>
Visit the <a href="http://codersgod.com/web-plugins/cg-scroll-to-top" rel="nofollow ugc">Coders God website</a> for documentation, support, and information.

CG Scroll To Top

CG Scroll To Top is an awesome wordpress plugin to scroll top of your webpage with custom animations and lot's of customizations.

WP To Top vs CG Scroll To Top