Coda is an amazing multipurpose program created by Panic Softare for the Mac OS platform; it combines a text and CSS editor, FTP program (based on the already wildly succesful FTP tool for Mac, Transmit), terminal, web previews of your files, and even has a built in version of The Web Programmers Desk Reference. I absolutely LOVE this program because it eliminates the need for having multiple applications open and streamlines my web editing and uploading process. Unfortunately for PC users, Coda is only available for Mac.
Adobe Creative Suite 3
Adobe released its biggest update to the Creative Suite line last year and it has made a lot of buzz all over the design world. My main go-to program in this package is Photoshop, but I also frequently use Illustrator, Flash (Adobe purchased the Flash suite from Macromedia) and their new tool called Bridge, which is a visual media management tool. Notable changes and additions to Photoshop include: Smart Filters (nondestructive editing of your documents), Rich painting and drawing toolset, 3D compositing and texture editing, more enhanced raw-image processing, and a larger range of supported file formats.
Firefox 2 & Firebug
As simple as a web browser is, Firefox really stands out in the crowd... with better security, several personalization filters, and my favorite, the ability to correctly display websites with XHTML, CCS, etc without the need for "IE hacks".
This is an extremely simple but vital utility for me, who is always needing to take good screenshots of websites for usage in our portfolio. Again, only available for Mac, but there are PC alternatives out there such as Snagit (http://www.techsmith.com/screen-capture.asp)