I don't use a TON of software but I try to do open source if it's available.
- PDF viewer: FoxIt Reader (free)
- Image editor: Photoshop (I found a disc in the lake)
- Development: LINQPad (bought this years ago, in like 2007, and the small fee was way worth it. Handy tool)
- Misc: UltraEdit (I've pirated this before but realized that's dumb so I bought it a couple years ago; again great tool and not that expensive in the scheme of things). Came with a compare tool too which is awesome. I'm used to BeyondCompare at work though which is just fantastic, though I think the UltraCompare one is pretty similar.
That's about it. I use several development softwares but they're free now (thankfully Visual Studio is, I love you Microsoft). Unity game development software is free for personal use too.