I could say the software is the fun part, but it's not. It’s another fun part. Or most of it is. See taking photos and creating images is the fun part. I use both hardware (Cameras, lenses, tripods etc) and software ( image processing) to follow my passion of creating beautiful images I can share with you; bringing the joy of my subjects into your life. Software also does the ho hum boring stuff of administration. It’s my data base, it lets me find things - most of the time, assuming I labelled it properly. I use Lightroom for that. It’s a very powerful program and does a good job of making up for my deficiencies in labelling by giving me many ways to search my files. Without it I’d be lost. It isn’t the only option, but I am familiar with it and between unexpected capabilities I stumble across and new upgrades there is plenty to keep me still interested. Of course, whilst it is a powerful cataloguing program it is so much more. It is perfect for doing the majority of post processing that an image needs to be a printable. Sometimes all it needs. It also allows you to do bulk editing on a series of shots.
To take an image however from the realms of a fabulous photograph, to combine it with others, to paint, to blend, to transform takes a bit more. My main workhorse is Photoshop. It’s so much of a standard that it’s a verb. It’s like I still hoover my carpet with a vacuum, even though my vacuum isn’t a Hoover. In fact, I cannot even remember what brand it is. So people often say something is photoshopped even when that bit of software hasn’t even had a sniff of the image. So other programs I use to ‘photoshop’ my images include Nik Filters, On 1, Topaz, Metabrush, Glaze, Distressed FX and one of my favourites on my iPad, Icolorama. I tend to bounce images around through several of them as some have particular strengths and others are one trick ponies and pull the lot together in Photoshop.