I used to use illegtimate software as well but then after a while I didn't feel right about it because it is stealing...especially if you're making money out of using that software.
That's why everything I use now is free.

I use GIMP sometimes. It's pretty good...but after almost 6 years of using Adobe Photoshop it's hard to get used to another program especially when hitting the short-cut keys in Photoshop almost became a reflex action.
For illustration, I like Inkscape. You can save the files in SVG format so there's XML compatibility right there.
The OS I use is Ubuntu Linux and it comes with a whole bunch of packages that are installable and that's all I need.
I've even stopped using Windows because I can't afford it (even if I could, I don't think I would have bought it. Not worth it IMO) but I have a small 5GB partition that has a very minimal installation of Windows on it so that I don't have too many compatibility issues with files that clients using Windows send me...but I haven't booted it for over 4 months.

This means I've also stopped playing games :/
I want to buy the Star Wars games from Lucas Arts though...Star Wars Pod Racer was nice

I'm glad there's so much open source software floating about. I've even started two open source projects at Sourceforge and I hope that once it's done, it will help someone out there so that I can give something back.