hackadelic

When you use a shortcode in a text widget to dynamically create its content, the shortcode may yield empty content in some contexts, leaving you with an ugly looking empty widget in your sidebar with nothing more than a title and a blank rectange.
What you want is a text widget that will only show up when it does have content. This is such a widget.
A use case when you will immediately benefit from <a href="http://hackadelic.com/solutions/wordpress/discreet-text-widget" title="Discreet Text Widget" rel="nofollow ugc">Discreet Text Widget</a> is when you want a <a href="http://hackadelic.com/solutions/wordpress/toc-boxes" title="Hackadelic SEO Table Of Contents" rel="nofollow ugc">Table of Contents</a> <a href="http://hackadelic.com/table-of-contents-in-the-sidebar" title="How To Add a Table Of Contents to the Sidebar" rel="nofollow ugc">in the sidebar</a>.
Check out the <a href="http://hackadelic.com/solutions/wordpress/discreet-text-widget" title="Discreet Text Widget" rel="nofollow ugc">plug-in homepage</a> for in-depth information about the plug-in.
<h3>License</h3>
This file is part of the Hackadelic Discreet Text Widget WordPress plugin.
Hackadelic Discreet Text Widget is free software: you can redistribute it and/or modify it under the terms of the <a href="http://www.fsf.org/licensing/licenses/agpl-3.0.html" rel="nofollow ugc">GNU Affero General Public License</a> as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
Hackadelic Discreet Text Widget is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with Hackadelic Discreet Text Widget. If not, see <a href="http://www.gnu.org/licenses/" rel="nofollow ugc">http://www.gnu.org/licenses/</a>.

Hackadelic Discreet Text Widget

A smarter text widget that can be used to display table of contents in the sidebar.

disinfor

A text widget based on the default WordPress text widget. Allows users to add custom classes to the widget container and the title tag.
It takes this: 
<h3 class=”widget-title”>
And allows you to do this: 
<h3 class=”widget-title custom-class custom-class-2 etc”>
It also allows users to add custom classes to the widget container.
NEW 
If the sidebar registration in your theme’s function file does not contain any HTML for before or after the title of the widget, this now will now fill that with an <code><h4></code> tag set.
<h3>General Information</h3>
This plugin is absolutely free to use. I made it for a specific personal purpose and decided to share with everyone else. I will try and update this for the future but can’t guarantee.

Text Widget with Class

A text widget based on the default Wordpress text widget. Allows users to add custom classes to the widget container and the title tag.

Hackadelic Discreet Text Widget vs Text Widget with Class