(somehow, in my mind, I see some cartoon character named "pixel" laid out dead on the floor ...... )
Each program is designed by someone for THEIR reasons. What you have to do is try them and find which one works for YOUR reasons. Some will seem "left handed" (commands seemingly hidden or not where you expect them, etc.); some seem overly complicated; they were not designed with you in mind.
What you are getting for advice is more of the "I use ...." rather than why the use, people try for validation rather than information.
This also depends on VERSION; Paint Shop Pro is at version 14 (X4) and if you were looking at version X2 or earlier things have changed somewhat; Lightroom 4 will be different from lightroom 3; Elements 10 is selling for about $50 in some places as 11 is expected soon, and I haven't heard anyone here mention Serif Photo Plus X5; serif free starter edition here http://www.softpedia.com/progDownload/AfterShot-Pro-Download-204435.html
(it's English, not American), PSP Ultimate includes Nik Color Efex Pro 3, picture tubes, etc)
I use an OLD PSP version 7 for simple stuff and for organizing because it is so incredibly simple to use; Elements 10 or PSP X3 for heavy duty work (PSP uses Adobe plug ins, filters, etc.) -- they fill my needs (I am not heavy on editing, 90% of what I do is cropping, sharpening and simple brightness / contrast and Red - green - blue adjustments and repair, mostly for other people's pics; and I rarely see the need for anything with the high powered tools; but that is my style of photography,
I do the work in the camera, (we used to call this "available light" - set up everything to be right when you take the shot). Some people will take 1,000's of shots at full auto and then do the choosing and editing at home, that is their style; some people play with a shot until it is unrecognizable from the original scene; that is their style
You have to find what works for YOU so do download the free trials (PSP X4 ultimate v. 18.104.22.1682has a 30 day free trial here http://www.softpedia.com/progDownload/AfterShot-Pro-Download-204435.html
as does Corel Aftershot Pro the workflow organizer 22.214.171.124 here http://www.softpedia.com/progDownload/AfterShot-Pro-Download-204435.html;
Adobe lightroom 4.o beta expires March 12 (will not run after that date) you need to see if they are announcing on that date or will have a newer Beta released
You have seen GIMP referred to, it;s FREE