Here's the (Macintosh) software I purchased in 2008:
1) Adobe CS3 Master Collection. (I bought this with the educational discount). I was originally going to buy just the web developer pack, but decided I might as well spend a little more and get everything. Big waste of money. Soundbooth (soemthing I was interested in) has almost no features. Dreamweaver, Fireworks, and Photoshop are the only apps I've used (primarily Fireworks). The UI is slow, painful, and non-standard -- not entirely their fault -- these are basically applications designed before OS X. On second thought, if you're charging $2500 or more, it is your fault. Adobe: you suck. Shit or get off the can.
2) Coda. Coda looks and feels like Apple's take on Dreamweaver. It lacks some of the features, but not enough for me to stop using Dreamweaver completely. If they did a Fireworks-type app I'd never use Adobe again.
3) SubEthaEdit. A nice little text editor (used by Coda). It's designed for real-time collaborative editing over the internet, though I haven't tried that. For some reason, it feels a little bit nicer than TextWrangler, though I don't know why.
4) Versions. A subversion browser. It's a little pricey (IMO), and yes, I know all the cool kids have switched to git. However, I still use svn for my repositories. Using a gui is easier (and more accurate) than typing out full pathnames, for tagging, etc.
5) Tax Cut 2007. Almost forgot about that, since I use it for a week and hopefully never again.