I use MS PhotoDraw2 (no longer made nor available) and have a hard time getting away from it, very happy. I know many here who use, and are happy with, Jasc Print Shop Pro 7. I have it, just can't get used to it. You know how it is with what we are comfortable with. I also have Adobe Photoshop Elements 1 (2 just came out) and same thing, can't get used to it. I think those two programs, for a casual user, basic yet still plenty powerful, will do most anything you might need.
I use Microsoft Photo Editor (not sure if it is still available or not) and mostly Adobe Photoshop. Most wouldn't need much more than the Photo Editor but it is fun to play a bit with Photoshop (it is costly though).
Found a neat program called QImage Pro (free to try for 30 days, then $39.95). Automatically sets up to get the most out of your paper without having to arrange it yourself. (ex., 3 4x6 or 2 5x7, 1 5x7 with 1 4x6). Great high end editing filters which I've only just begun to use much less understand.