MUST HAVE mac apps ! ! ! ! ! ! !

So i'm fairly new to macs and I find new and very interesting programs everyday. I KNOW there are some out there that I haven't seen yet. So post up your favorite and essential apps.

Besides the usual, like iTunes, Firefox, MS Office mine are:

Adium - best chat, except no video
iPodDisk - gets music off my ipod
Transmit - my best FTP experience ever
VLC - the do it all media player
iCal and iSync - yeah they come with the mac, but I just recently found them and use them to sync to my mobile phone.. SO usefull.