If you are a hobbyist or don't really want to buy the Adobe CS here is some free Open Source alternatives to it
Replace Photoshop with...
GIMP(Windows, Mac, Unix)
GIMP stands for GNU Image Manuipulation Program. The program has the ability to edit bitmap images and photos. It saves files in formats that will work with other bitmap editors, including Photoshop (jpeg, tiff, gif...). There is also a modified version of the client for Windows called GIMPshop, which "skins" the interface to emulate Photoshop.
Replace Illustrator with...
Inkscape (Windows, Mac, Linux)
This program creates scalable vector artwork. It can import and export SVG, Illustrator (.ai), PDF files, and also handle many common raster format files (jpeg, png, gif..).
Replace InDesign with...
Scribus (Windows, Mac, Linux)
This open source program is designed for desktop publishing. This program supports PDF/X-3 standards and comes with a limited amount of vector tools. It supports SVG importing and Open Type fonts.
Replace Flash with....
Synfig (Windows, Mac, Linux)
Flash serves a dual purpose for designers, as a means to animate/present content or to use as an interface. It can export to a variety of video formats, including Flash (.swf), mpeg, and SVG. This program also supports ActionScript.
Replace Dreamweaver with...
Nvu(Windows, Mac, Linux)
This HTML editor allows code view and WYSIWYG design view, similar to the way Dreamweaver does it. It also allows users to handle their files neatly, integrate forms, and more. This is a great program for those learning web design. It also offers a clean source code view for the people that like to create their HTML from scratch.
There is a lot more in the Creative Suite but I find these the most useful programs for what I do.
Hope this helped thanks!
-Nexus