Mac OS X Must Haves

In no particular order:

• Adium - A Cocoa-ized port of GAIM (Gnu AOL(?) Instant Messenger). Like iChat, but allows you to connect to multiple chat services simultaneously.
  
  
• Camino - Currently the best browsing experience on the Mac. Based on the same Mozilla code base that Firefox is, but it's user interface is natively OS X. Apple's Safari is a close 2nd, but Camino is compatible with more site
  
  
• Spotlight - Spotlight is built into OS X 10.4. I used to recommend Black Tree's Quicksilver, but I've discovered that Spotlight is nearly as convenient and doesn't consume the system resources that Quicksilver does. Command (i.e. the Apple Key) + Space Bar, then type the first four to five letters of what you're looking for and then arrow down to it and press enter. It's bliss, you never have to remember where you stored a document or installed an application again.
  
  
• Fugu - For SFTP/SCP, now if only it did plain FTP too.
  
  
• VLC - Video LAN Client, plays video formats that Quicktime Player won't
  
  
• TextEdit - Seriously, the best free text editor/word processor for OS X comes free with the OS. The version in Tiger is amazing.
  
  
• Sound Studio - Looks like this has been sold to Freeverse. I got it free with my iBook or PowerBook a couple of years ago and it has been indispensable for recording old out-of-print cassettes and LPs and putting them on CD.
  
  
• Freecell
  So, Windows doesn't come with an SSH client? Well, OS X doesn't come with any good card games. This free version of freecell helps to close that gap.
  
  
• Mike's Cards Lite
  OS X also doesn't come with a version of Solitaire (Klondike), however, Mike's Cards Lite fills that void as well as coming with 6 other Solitaire games such as Arcade Poke, Forty Thieves, Go Fish, La Belle Lucie, Spider, and The Towers.