This plugin easily integrates the <a href="http://code.google.com/p/syntaxhighlighter" rel="nofollow ugc">Google Syntax Highlighter</a> by <a href="http://code.google.com/u/alex.gorbatchev" rel="nofollow ugc">Alex Gorbatchev</a> into WordPress.
<h4>Feature summary</h4>
<ul>
<li>100% client side, no server dependency</li>
<li>Multiple languages support</li>
<li>Wide browser support</li>
<li>Very lightweight</li>
</ul>
<h4>Languages Supported</h4>
<ul>
<li>C++ (cpp, c, c++)</li>
<li>C# (c#, c-sharp, csharp)</li>
<li>CSS (css)</li>
<li>Delphi (delphi, pascal)</li>
<li>Java (java)</li>
<li>Java Script (js, jscript, javascript)</li>
<li>PHP (php)</li>
<li>Python (py, python)</li>
<li>Ruby (rb, ruby, rails, ror)</li>
<li>Sql (sql)</li>
<li>VB (vb, vb.net)</li>
<li>XML/HTML (xml, html, xhtml, xslt)</li>
</ul>

Google Syntax Highlighter for WordPress

This plugin makes using the Google Syntax highlighter by Alex Gorbatchev to highlight code snippets within WordPress simple.

leo108

This plugin not only provides you syntax-highlighter , but also add a textarea and a button in the post page . 
you just have to select the language , add code to the textarea and click the ‘OK’ button , and you will get 
your code highlighted in your atricle. 
这个插件不仅仅提供了代码高亮，还在编辑页面增加了一个代码框和一个按钮，你只要选择好你的代码语言，把代码贴入代码框， 
再点击一下OK按钮，你的带高亮的代码就会被插入到文章里去。
Supported Languge: 
 Bash 
 C 
 C++ 
 C# 
 CSS 
 Delphi 
 Diff 
 Erlang 
 Groovy 
 HTML 
 Java 
 Javascript 
 Perl 
 PHP 
 PowerShell 
 Python 
 Ruby 
 SQL 
 VisualBasic 
 VB.NET 
 XML

Syntax Highlighter++

You can add code with syntax highlighter easily when you are editing an article. 方便的代码高亮插件。

Google Syntax Highlighter for WordPress vs Syntax Highlighter++