Keith S.

The best new feature in WordPress 2.3 is the integration of tagging into the core of WordPress. However, the tag cloud widget & functions that are included leaves a lot to be desired. So, with time on my hands, I decided to whip up my own version of the tag cloud that lets you configure the tag cloud with all the customizations (well, almost, see below) the tag cloud template tag allows.
You can find the plugin home page (and leave comments) <a href="http://keithsolomon.net/ctc/" rel="nofollow ugc">here</a>.
<h3>NOTE</h3>
Development on this plugin has STOPPED! I am looking for someone to take it over. Find more info <a href="http://wp.me/p4xrG-7q" rel="nofollow ugc">here</a>
<h3>Upgrade</h3>
I suggest using the built-in WordPress plugin update feature, but to manually upgrade, follow these instructions: 
1. Deactivate the plugin in the WordPress admin menu. 
2. Delete the existing <code>tag-cloud.php</code> file from the <code>/wp-content/plugins</code> folder. 
3. Upload the <code>tag_cloud</code> folder to the <code>/wp-content/plugins/</code> directory. 
4. Activate <code>Configurable Tag Cloud</code> through the ‘Plugins’ menu in WordPress and add the widget to your sidebar. 
5. (Optional) Add <code>ctc()</code> template tag to your theme. Can be configured either via the Options menu, or via parameters in the template tag.

Configurable Tag Cloud (CTC)

Display a tag cloud customized with your preferences in the sidebar.

The Krotek

Customizable widget and shortcode to display tag cloud anywhere you want. You can use it as standard tag cloud widget, as shortcode in any post or page, or both ways. Tons of options allow you to fine tune cloud layout to your needs.
STANDARD FEATURES
<ul>
<li>Display list of post, category or link category tags.</li>
<li>Define number of tags to be displayed.</li>
<li>Set custom tag separator.</li>
<li>Select tag taxonomy: posts, categories or link categories.</li>
<li>Choose cloud mode: shortcode only, widget only or both.</li>
</ul>
PREMIUM FEATURES
<ul>
<li>Define smallest and largest tag size.</li>
<li>Select size unit: px, pt, em or percent.</li>
<li>Choose layout: standard flat cloud or unordered list.</li>
<li>Order tags by name or count.</li>
<li>Sort tags ascending, descending or randomize.</li>
<li>Define list of tags to exclude from cloud or include only.</li>
</ul>
You can purchase Premium version <a href="https://thekrotek.com/wordpress-extensions/tag-cloud" rel="nofollow ugc">here</a>.

Custom Tag Cloud

...but it at least is a little better than the one that comes with WordPress.

Free version is not very customizable...

Customizable widget and shortcode to display tag cloud anywhere you want.

Configurable Tag Cloud (CTC) vs Custom Tag Cloud