Aaron D. Campbell

A widget that properly handles twitter feeds, including parsing @username, #hashtag, and URLs into links. It supports displaying profiles images, and even lets you control whether to display the time and date of a tweet or how log ago it happened (about 5 hours ago, etc).
<a href="http://aarondcampbell.com/wordpress-plugin/twitter-widget-pro/" rel="nofollow ugc">Twitter Widget Pro</a>

Twitter Widget Pro

A widget that properly handles twitter feeds, including parsing @username, #hashtags, and URLs into links.

pathartl

A stylized Twitter widget. I created this plugin because I wanted a better looking widget on my personal blog. It’s not as complex as some other plugins, but it serves its purpose. The widget will adjust itself to the width of the sidebar automatically. It does use some CSS3 for rounded corners and transitioning, but it will look completely fine on other browsers. It also auto updates the Twitter feed for a specified amount of time which can be changed in the settings page.

Twitter Widget Pro vs Tweeter!