I use Cosmigo Pro Motion, but sometimes I'll do edits or doodles in KolourPaint (Think MSPaint, but with hotkeys and more undo).
I tried using the Gimp once, it was probably the worst pixel editor I've ever used. Graphics Gale was probably the second worst. I can't really remember why these days, but both left me feeling very sour while trying to use them.
Grafx2 was really nice, I used that for awhile, if you can't afford Pro Motion for whatever reason, I'd definitely suggest using that. PM being "dead software" doesn't change the fact that it works really great, and has saved me probably entire days or maybe even weeks of time.