So now I got a new mac recently, and decided to keep track of what freeware apps I use and can recommend. Ready? 

System & Usability

Blacktree-quicksilver
Quicksilver is usefull, timesaving and slick. Forget Finder ;).

macfuse – Google Code
MacFuse lets you use 3rd party Filesystems, Nerdy? yes, but better than mobileme iDisk.

Macfusion: The world in your Finder
This is what makes macfuse useable for anyone. Add your (web) server to your finder, just like your iDisk (but hopefully faster ;)).

Growl
The best notification system there is for the mac. 

SSHKeychain – About
It’s not a keychain. It’s a Swiss Armyknife ;). You can easily manage SSH keys and make tunnels (automatically !).

AppleScript to enable SOCKS proxy on Mac OS X « Blog « Peter Upfold
The most usefull script to switch your mac’s proxy settings. Very handy in combination with sshkeychain and quicksilver.

iTerm
Terminal application, forget terminal.app ;).

LiquidCD
Burn your DVD’s and CD’s without a learning curve. 

Connectivity

Adium – Download
Adium is made of Win. The slickest, most fun client to use for most IM networks. No cam support, though.

aMSN – Opening your communication
Not the best client (see above), but webcam support for MSN.

Cyberduck
File transfer client, supports most mayor protocols.

SecretStaircase – NatsuLion
Twitter client, which can use Growl. It keeps mee informed, but won’t distract me as much as the other available clients out there.

CoRD: Remote Desktop for Mac OS X
Very good and stable RDP client, for all your RDP fun.

site-tip: Pure Mac: Remote Access – Software for Macintosh
This page lists a fine selection of the best connectivity software.

Other

KeePassX
KeePass password manager for OSX. Store them securely.

☆ Desktoptopia ☆
Has a great selection of wallpapers, the app changes your desktop background frequently. 

VLC media player�
VLC plays anything, its a very fine mediaplayer.

Last.fm
The last.fm app scrobbles tracks and you can listen to music from last.fm.

Twittervision Screen Saver
The ultimate Twitter screensaver for OSX.

Commercial Software
Worth the money :)! 

Parallels
Run any OS on your mac. Works great with Windows. No reboots :)!

TextMate — The Missing Editor for Mac OS X
It really IS the missing code editor for OSX. Great for coders.

Apple – iWork
iWork, its the best way to create good looking documents and presentations!

Your suggestions

Grand Perspectiv
Find your biggest files easily. Suggestion from @benstien .