Wow, that photo looks wonderful!
I mostly use PaintShop Pro, only because I have it on my PC and I can't be bothered buying another program.
I don't use it a lot though because for some reason it never occurs to me to work on my photos. I just delete them if they don't look good.
At work, we have Photoshop and I have to admit I don't like it. I bet it's a wonderful program but it has so many options that I get lost in all the buttons and menu options every time I use it.
I do have to do quite a bit of work with pictures (not photos) at work though, and I generally use Irfanview. It's free, it's small, and it's very very useful when you have to do batch jobs!