I use Photoshop 7. It is old,but I find it much more less complicated than CS(whatever the number is)...I have Gimp too but I never se it 'cause it is so weird and complicated for me(this happens when you get used to actually see and manage the layers).I'm a photoshop person and that's it :P
I need the Adobe Creative Suite for my work. That's the reason I'm used to Photoshop CS 4.
I installed Gimp on my Laptop, but it can't handle alpha channels when you want to export them as bumpmaps for .dds files. I love creating CAW terrains.