For years the gold standard for photo editing software has been Adobe's PhotoShop. I've had PhotoShop since version 4. While it can do virtually anything you want, it does have a very steep learning curve.
I've switched my primary photo editing software to JASC's Paint Shop Pro version 9. One of my complaints with PhotoShop has been the auto correction never quite produces what I think it should and I've never really mastered setting the levels manually. With Paint Shop Pro (PSP), I've found that for most pictures I like the results that PSP produces automatically. And PSP has a nice batch mode that lets me take a whole card full of pictures and have PSP fix them up automatically.
What really caught my eye with this version is that frequently I don't take pictures straight on, resulting in images that are distorted or with funny perspective (taking a picture of the Empire State Building without tilting up to get it all is practically impossible). With PSP you can use one of its tools to adjust the horizon or make a trapezoid picture in a museum rectangular again. And it doesn't take a digital editing class to figure it out (I did need the help file to find the icon I was looking for but not to use the feature).
The last new feature I like is called background eraser. It makes it easy to take a product photo and eliminate any background that might be part of the photo (handy if you want to substitute a new background). You can paint part of a background and PSP will handle extending that selection to include everything up to the edge of an object. No more zooming up to see individual pixels and the painstaking process of clicking individual pixels off.