PS 7, I got it at an educator's technology convention, I home-school my kids, I also picked up illustraitor, Bryce and Poser.. I got all 4 for about what PhotoShop retails for. @ $650
photoshop 6.0 and 7.0 .... and since we used these programs at school and we needed them at home to work... well, we didn't pay... teachers made copy for us^^.
I use ps 7 , i thought about upgrading to CS but the new features (in photoshop alone) arent enough yet for me to spend the money to upgrade, maybe in the next release :)