Apart from the iLife and iWork packages, here's what else lurks in my Dock:
Browsers: Firefox (interaction with ISP, finances) and Safari
As far as music related software is concerned, I use iTunes (of course!) as well as:
xACT (encode/decode compressed files)
Toast Titanium (burning)
Other handy apps:
Kindle (again, integrates nicely with iPad version)
ToDo (Task management)
Fluid is a very handy app, free for the basic version, $4.99 for additional features which will create stand alone apps for websites you visit regularly. I’ve used it to do that for FaceBook, Blogger and Twitter.
1Password (Creates strong passwords, remembers them, and pastes them directly into log in screens on your web browser. Invaluable, with versions for Mac, Windows, iPhone, iPad and Android).
iClip (Clipboard manager, very handy)
Yum (Recipes, no longer available. I’ll probably eventually transfer the content to Bento, but there’s a great wing of it, so while it continues to work I’ll continue to use Yum, won’t I?).