alialhoasy

This plugin colors and decorates the tags and makes them more aesthetic than the default word cloud.
At a glance, this plugin adds the following:
<ul>
<li>There are 7 fields to choose custom colors.</li>
<li>You can specify the number of words.</li>
</ul>

Keywords Cloud

To add a widget that shows the tags formatted, colored and of different sizes.

conis

This plugin can high light keyword after someone searchecd it, which supports the search engines like google, baidu, ask, yahoo&bing. 
1.the highlight words are from the link of the search engine 
2.every key word is added with a link, clicking the link can search in the site 
3.on the top of the article show the key words which users are searching 
4.high light the searching result 
5.the highlight words are showed in the content and the excerpt
more information, pls visit(English):<a href="http://conis.cn/1365/" rel="nofollow ugc">http://conis.cn/1365/</a> 
国内的朋友请访问我的博客获取更的信息 <a href="http://conis.cn/1344/" rel="nofollow ugc">http://conis.cn/1344/</a>

wp-markKeyword

This plugin can high light keyword after someone searchecd it, which supports the search engines like google, baidu, ask, yahoo&bing.

Keywords Cloud vs wp-markKeyword