Adium: A multiplatform chat client. Skins and plugins galore. Don’t need to look anywhere else, this is the app you need.

Growl: A system notification thingy. Windows don’t growl. Get it and set it.

Disc burning: Toast for kamasutra, Disco for quickies.

Fission: A quick, but clean audio editor by Roque Amoeba. If you’re into audio, you should definitely check their stuff out.

Flip4mac: Windows media codec. You need this to watch or listen to Windows Media content with Quicktime.

Perian: One of the first things I install. It adds native support for popular video formats like xvid, divx, etc to Quicktime.

VLC: There isn’t a media life without VLC. Doesn’t matter which platform you’re on.

VisualHub: This is your hub for quick video conversions.

ffmpegX: This is what you need if you are serious about video conversions.

iStat: System resources widget or menubar thingy. Take your pick.. My pick is iStat Pro. Get it and watch what your Mac is doing while you are trying to figure out how silent it is compared to that POS you left behind..

Little Snitch: Think of this little biatch as an outgoing firewall. If some software is calling home, this baby will let you decide if it may or not..

UnrarX: Run of the mill rar/par thingy.

The Unarchiver: Run of the mill archive extraction thingy supporting many formats.

MacPAR deLuxe: If you’re into usenet and parity files, you need this..

Split & Concat: Kinda like HJSplit.

Textwrangler: Text editor on steroids.

Max: Audio converter. If you wanna rip that cd or convert that file to your preferred format, you need this. Also check out AudialHub.

MP3-Info CMM: This finder plugin lets you right click on an mp3 file and peek into its tag.

Skitch: Quick image editor, screenshot grabber, image sharing app and webservice combo. Lovely!

Pixelmator: Even if you are a Photoshop guru, you still should take a look at this image editing app.

Speed Download: Download Manager. First thing I bought when I switched.

Transmission: Into torrents? This is your client.

TV Shows: You don’t need to manually download torrent files for TV shows anymore. New version coming soon..

Yummy FTP: There’s a few ftp clients out there for the Mac but this was my choice..

OS X XBMC: If you think you will miss Windows Media Center, you are mistaken. Or if you have an Xbox with XBMC running on it, now you can do HD thanks to the OSXBMC project.

Appzapper: What if you install these and don’t like some of them? Yeah, yeah.. We’ve all heard it before.. In OS X, you can move the application you wanna delete to the trash folder and that’s it.
No it isn’t.

If you do that, a bunch of other files like preferences files, etc stay behind. Zap ‘em with Appzapper so that the app and the related files are history..