The most essential software to make your Mac more awesome. Not having some of these tools is like having half a Mac. Others are just plain fun, You have a very cool computer.
Adium, Free IM - Instant Messaging

Adium is a free instant messaging application for Mac OS X that can connect to AIM, MSN, Jabber, Yahoo, and more.
Download
Miro Mac Video Player

Miro is a popular, free, and open internet TV application. It brings video channels from thousands of sources and has more free HD than any other platform.
Download
Miro Best Free Video Converter for Mac

Convert any type of video to mp4 or theora. Convert any video for use with iPhone, iPod, Android, etc. Very clean, easy to use interface.
Download
Quicksilver Application Launching

Quicksilver is a computer utility software program for Mac OS X. It is essentially a graphical shell for the Mac OS X operating system aimed at increasing user efficiency.
Download
AppFresh Auto Update for Mac

AppFresh helps you to keep all applications, widgets, preference panes and application plugins installed on your Mac up to date
Download
OpenOffice

OpenOffice is a full-featured, office suite compatible with Microsoft Word, Powerpoint, and Excel. Plus it's 100% free and open source. Friends don't let friends pay for Microsoft Office.
Download
VLC

Plays more video files than most players: Quicktime, AVI, DIVX, OGG, and more. Great for playing DVDs too.
Download
xPad, Writing and Office

For most writing a word processor is overkill. xPad is the perfect simple alternative. Your notes sit in a sidebar and save automatically when you quit. Way better than stickies or TextEdit.
Download
Mozilla Firefox

The premier free, open-source browser, considered by many to be the world's best. Clutch for sites that don't support Safari. What sets it apart from Safari is the huge universe of plugins and extensions.
Download
Camino

Based on the same Mozilla foundation as Firefox, Camino is a more native OS X app. Fast and simple.
Download
Vidalia

Rock-solid anonymous web browsing for everyone. This
TOR frontend keeps you anonymous on the web using open source software and military-grade techniques. To use with Firefox see:
TorButton.
Download
Basecamp

This is web software, but it will become as central to your work experience as any desktop app. Seriously, Basecamp will make you more productive and change the way your organization works. Try it!
Webpage

What Basecamp is for teams, Backpack is for individuals.
Webpage
Highrise

Simple customer relationship management--really simple. Another great piece of web software.
Webpage
Parallels

Run Windows programs on your computer in their own window at full speed. You have a top of the line Intel chip; you deserve it.
Download
Q Emulator

Not as polished as Parallels, but 100% free and open source. Lets you run Windows on G4 and G5 Macs too (though this will be slow).
Download
Burn

Burns to DVD, VCD, and SVCD. Take your downloaded videos and burn them to disks you can watch on regular DVD players. For VCD and SVCD you don't even need a DVD burner. Free and open source!
Download
Handbrake

DVD ripper with MPEG-4 / H.264 encoding. The simplest way to save DVDs on your computer.
Download
Transmission

A rock solid torrent downloader. 100% free and open source (no annoying nags).
Download
xTorrent

Integrated search makes this an awesome Bittorrent client, and makes you very happy to have a Mac.
Download
SolarSeek

Soulseek filesharing for Mac. Never be without music. 100% free and open source.
Download
Seashore

"Photoshop" your photos without buying Photoshop. 100% free and open source, based on the open source image editor "Gimp".
Download
Xee

Fast image viewer and image browser.
Download
Senuti

Get music off of your iPod onto any computer.
Download
iPodDisk

Copy music off your iPod in the finder, like a regular disk drive.
Download
Skype

Talk with any Skype user for free. Buy some credits and you can call any number in the world, cheap. Perfect for when your cellphone is out of batteries... or on the other side of the room, lazy.
Download
Aurora

Use your Mac as an alarm clock and wake up to your favorite music. Wakes from sleep, so no need to leave your computer on all night.
Download
Sixty Force

Trouble finding good games for you Mac? Then turn it into a Nintendo64! MarioKart works great, even on a Powerbook G4.
Download
Nestopia

Kick it old school with this NES emulator for Mac.
Download
Ableton Live

For anyone who ever wanted to make a remix, DJ a party, or play with beats. A great manual, good tutorials and a super slick interface make Live so easy to learn. Free demo (hint: use
AudioHijack for saving).
Download
iEatBrainz

iEatBrainz automatically adds the right song, artist, and album info to your iTunes music. No more messy iTunes Library.
Download
Google Earth

The 3D map of the world that just gets better and better...and creepier. Total must-have.
Download
KisMac

The best wireless scanner for Mac. Find wireless access when you're on the go. 100% free and open source.
Download
NetNewsWire

The slick integration of tabbed browsing makes this RSS reader our top pick.
Download
Vienna

Very nice, native RSS client. 100% free and open source.
Download
Transmit

The best FTP program for Mac.
Download
Cyberduck

Very good all-around ftp program. 100% free and open source.
Download
The Unarchiver

Uncompress RAR, 7zip, tar, and bz2 files on your Mac. Many new Mac users will be puzzled the first time they download a RAR file. Do them a favor and download UnRarX for them!
Download
Colloquy

Great IRC client. 100% free and open source.
Download
WaveMaker

An open-source visual development tool for building great-looking web and cloud applications.
Download