After the Deadline - I wish I'd found this ages ago. If you do a lot of writing on the web, this is the best contextual spell-checker and grammar fixer.
Basecamp - at work, this is where we keep track of all of our projects (milestones, messages, to do lists)
Dreamweaver - I'm not a big fan of Adobe, but I use this HTML editor every day (especially helpful for table layouts in HTML emails)
Fireworks - this goes with Dreamweaver; still my favorite "quick and dirty" image editor (both bitmaps and vectors)
Freshbooks - in my side business, this is how I stay organized with sending invoices and getting paid
Google Apps - I use Google for email and calendars, mostly. Great email service.
Highrise - used to track contacts, conversations, and tasks related to contacts
iPhone 3G - most important device I carry
Screenflow - a really great Mac app that allows you to create screencasts, and video tutorials
Seismic Desktop - My favorite desktop app for Twitter and Facebook (largely because it supports multiple accounts)
Skitch - I use this about 10x a day. The best screen capturing app for a Mac.
TextExpander - I probably use this 25x a day. Expands a shortcode to a specific piece of text (ie. “AAmailing” becomes the full mailing address).
Twitter - I'm still a big fan. Micro conversations, completely searchable, makes it easy to share content.
Wordpress - last on the list, but probably first in terms of importance, is the Wordpress platform. I use it personally every day and also use it as a CMS for people that buy a website from me.