There is a plethora of Twitter clients out there that all have their own special features or areas they excel in, but which is the best for you as a Mac user?

TweetDeck - It is one of the most popular twitter clients with large user-base. Multi-column twitter timelines, powerful twitter search and custom groups makes it an ideal twitter client for power users. It has a rich URL shortening support. You can also update your Facebook account via Tweetdeck. You can also use the TwitScoop cloud to keep you updated about what's hot on twitter. Tweetdeck updates itself automatically and has various customization options including custom colors. The only issue that is frequently raised by users is the memory usage. TweetDeck is available for Mac, Windows and Linux platform.

Twidget - Currently, it is only available for Mac platform. This light weight twitter client is ideal for casual users who doesn't have large network of active followers. Some of the features include auto-updating timelines, alerts for new tweets, new version availability alert, links to DM's and twitter contacts and much more. You can also favorite selective tweets directly from within the refreshing timeline. Twidget also allows you to collapse and expand the timeline window at will. Future versions will have Growl notifications, audible notifications, URL shortening support, multiple language support and flexible resizing option.

Twitterrific - This twitter client has stunning interface and is light on system resources. It supports multiple twitter accounts and provides access to user profile pages with a single click. It supports audible alerts and keyboard shortcuts. You can also set custom hotkey for showing and hiding tweets. twitterrific also supports deletion of your own tweets and has customizable timeline auto-refresh intervals. Replies and direct messages are displayed inline highlighted with different colors for easy readability. Through custom settings you can also set window auto-hiding. There are two more variants of twitterrific for iPhone and iPod Touch.

Tweetie - This Mac-only client is my personal favorite. Like Twitterrific it stays tucked in the menubar when you're not using it and when someone tweets the menu icon lights up to let you know. Custom hotkey for showing and hiding the window included, all the other standard features as well, but my favorite part is that it has bit.ly, TinyURL, is.gd, tr.im, and DiggBar integration for URL shortening services. Also support for TwitPic, yFrog, Twitgoo, Posterous, img.ly, and pix.im integration for image services!