Application Recommendations Part 3 - OS X Applications

The OS X software library continues to grow. However it's size still pales in comparison of the amount of software available on the Windows side. Fortunately for what it lacks in quantity it tends to make up for in quality. Most applications in OS X often have an emphasis on User Interface design which make using OS X applications a very different experience then using the common Windows one.
Apple bundles a very valuable amount of software with it's computers and operating systems. I suggest you look through these (all found in the Applications folder) before pursuing third party alternatives.
Lastly, although the Windows versions of Quicktime and iTunes leave much to be desired. I have found that their OS X counterparts function better.

• I like the LotsaWater and the Filigree screen savers.
• Adium is an extremely customizable Instant Messaging Meta Client.
• Transmission is a well designed Bit Torrent Client.
• Webkit Nightly Builds are development builds of safari that are frequently updated and tweaked by the developers.
• Safari Adblock is a plug-in for Safari that blocks ads.
• Safari Tabs adds additional Firefox inspired tab options for Safari.
• InquisitorX improves the Google search field in the top right of Safari's interface.
• The Unarchiver is a replacement for OS X's built in uncompressing tool thats adds the ability to uncompress additional formats.
• Xee is an image viewer that can open almost any format.
• Onyx is a general maintenance, repair, cleaning and customization tool for OS X.
• iStat Menues adds informative (and very comprehensive) statistics about your computer to the top of the menu bar. Ram and CPU usage, hard drive read/writes, fan speeds, temperature sensor information, voltages, current and more.
• Gmail Notifier to keep track of your Gmail.
• VLC will play many different, obscure and even broken video files. As well Perian will allow Apple's default Quicktime software to play many additional video formats.
• Flip4Mac allows Quicktime to open Windows Media files.
• SmartSleep is for Mac notebooks and tweaks the default sleep/hibernate settings. The "SmartSleep state" option is recommended, read about it on his site.
  
• SMCFanControl allows you to manually ajust the fan speeds of your Mac.
• Lab Tick allows you to manually ajust the keyboard backlighting on your Mac notebooks.
• Growl ties into many popular OS X applications and creates non-intrusive and customizable notifications for application events.
  
• Quicksilver, if you choose to accept it. Will change the way you use a computer. After a short adaptive period you will find yourself wishing every computer had this built in. Further Explanation.
  
• iStumbler is a wireless network sniffing software.
  
• Remote Desktop Connection 2 is Microsoft's Remote Desktop protocol client for OS X.
  

A couple sites good for finding software for OS X:
Versiontracker
iusethis