I use Illustrator for Layout design, Photoshop to touch up images.
For webdesign, I use Illustrator to create cels, which i then import to dreamweaver, and for flash I use SwishMAX.
I use the whole Adobe web premium CS3 plus inDesign for different needs. I like Illustrator the best but got started on Fireworks and Photoshop first. I've dabbled in Gimp back in 2004 but haven't gotten around to using it since I acquired Adobe CS.