Much like @GamedevCala, there is always a pad of paper and a pencil at hand… I personally like to believe that in thousands of years time someone will discover my scribblings and believe that I was indeed a genius, just too far ahead of my time…
Visual Studio 2015 - wouldn’t be without it… just wish it would launch faster from Unity, sometimes it takes so long MonoDev actually loads?!
Macromedia Fireworks MX - old but trusty
Photoshop CS something or other - but lack the necessary skills
Blender - but not yet delved into it’s 3D wizardry
Pen and Paper
Unity
UE4
Blender
Gimp
Sourcetree
BitBucket
Google Drive/Docs
Microsoft Office
Asana
Visual Studio
All of them are self explanatory. Not everyone may know what Asana is. It is project management software. I don’t use all of its power just for myself but it is useful for planning and giving myself deadlines.
PC
Unity
Visual Studio Community Edition
Gamemaker (Now moved to Unity so not used since)
Notepad++
Blender (not done a lot in it yet)
Spriter Pro
Paint Shop Pro X8 (great alternative to Photoshop and with coupons got it for £54!) very pleased with it.
Substance Painter 2, Bitmap2Material, Substance Designer 5
Aesprite
Sonar Steam Edition
Sonar Professional + VST instruments
Libre Office ( I use the draw program a lot for flowcharts)
GSRichCopy360 (for copying Dev stuff to my archive drive and NAS as regular intervals)
PostImage (essential for forum images)
XMind 7 (for mind maps, but not neede it yet)
4 note books with fineline pens (Essential!)
IPAD
Procreate
Sketchbook Pro
a couple of Sprite apps but I can’t be arsed to get my ipad and find out what they are called!