You probably need Office anyway, but I find that I like to use it in read-only mode. If you think you might be ready to divorce MSOffice, look carefully at iWork (Apple's Office: awesomer in many ways, incompatibler in others). In particular, I've heard really good things about Keynote, their version of Powerpoint. If you want to divorce Word in particular there are a /lot/ of worthy suitors (Bean, WriteRoom, Scrivener...) you can shack up with. Which word processor you date next depends on what you particularly hate about Word. I think we're stuck with Excel, though I could be wrong.
You'll probly want to install Fink, Fink commander and the Developer Tools (on your Leopard CD, or http://www.apple.com/downloads/macosx/development_tools/), following the instructions on the Fink page. Even if you rarely use it, an alpha geek like you needs to have the command line as an option.
- Carbon Emacs
- If emacs doesn't run through your veins and you need to do any program editing, Textmate will make you really, really happy
- Play windows media in quicktime
- Flickr export from iPhoto
- TVShows (hasn't been updated in a whiles but it's great for auto-torrenting your TV shows)
- Mozy (free 2GB online backup): make sure you choose the free plan: click "Home Users on the right, then "MozyHome Free" on the left.
- Quicksilver, more info. (Is quicksilver still essential? or does the new Spotlight supersede it? Now is when I reveal my dirty secret: I'm still using Tiger. My brief experiences with Leopard say Quicksilver is still faster and more fluid.)
Quicksilver and Exposé are the hardest things to explain to a new switcher yet are two of the more transformative. Leave Exposé switched on and make yourself love it: you will, and quickly. Same thing with Quicksilver. Even if you only use it for app launching it's ridiculously faster-ing.
- Candybar -- "What if I told you you could make your hard drive and dock icons all look like Dr. Who characters. Is that something you'd be interested in?" If the answer to that is "yes", here you are. (I don't use this, I'm just guessing B in particular might)
- Acorn is the best Super simple photo editor, when you need more than iPhoto, less than Photoshop that I've found