If you're cheap like me, you want good free stuff. Here's a list of all my favorite good free things.
Bitmap/Raster Graphics: Paint.NET,Pinta, Gimp, Krita, MyPaint
Pixel art: Aseprite (Pre-compiled binaries cost, but you can download the source and compile for free)
Drawing: MediBand Paint Pro
Vector Graphics: Inkscape, Pencil Project
Online bitmap/PDF/.sketchpad (whatever that is): Sketch.io Sketchpad
Diagrams : draw.io
Clean interface with a few non-intrusive ads (no account required): Cubeupload
Professional-looking host with a few ads (needs account): Photobucket
In-browser or offline, automatic uploading: Lightshot
Offline only, also takes animated GIFs: Gyazo (NOTE: I gained a virus soon after installing this. However, nobody else has had issues. Most likely safe, but be careful.)
Windows-only, no automatic upload: Snipping Tool (Most likely came with Windows)
Mac-only, no automatic upload: CMD+SHIFT+4 and select area
Free game art and sounds: OpenGameArt, Kenney Assets
Popular & Often-used: Youtube
Less comments, more video: Vimeo
Also has minor editing ability: VLC
Windows only: MPC-HC
Difficult to use, tons of options and features, no watermark: OBS (Open Broadcaster Software) (Also does live-streams)
Easy to use, not many options, has watermark: Bandicam
3D Keyframe animation (and modeling): Blender
Difficult to use, all-you-can eat buffet of features: Lightworks (There is a paid version of lightworks. Just get the free one. See the blue "Lightworks Free" header on the homepage.), DaVinci Resolve Primarily for colour grading, but has a fairly robust video editing component as well.
Easy to use basic features: Windows Movie Maker, iMovie (comes free with mac computers)
(And also spreadsheets, presentations, etc. Basically free Microsoft Office.)
Full-featured online editor with auto-save, live multi-person editing, and more: Google Docs (Also known as Google Drive. Docs and drive aren't technically the same thing, but they pretty much are. I don't understand either.)
Offline Editor: LibreOffice
Code for the front-end web (HTML, CSS, JS, etc): Brackets
Online JS/HTML/CSS: JSFiddle, Codepen
General Code (all languages): Atom, Sublime Text, [Notepad++] (https://notepad-plus-plus.org)
IDEs for most languages: JetBrains (free if you're a student, paid otherwise)
Beginners' Lanuage and Editor: Scratch (Great community for kids)
Full 3D engines: Unity, Unreal Engine (Free for personal use, licenses and revenue sharing for commercial use.)
Lightweight HTML5 game engine: Phaser
Windows: Cmder
OS X: iTerm2
Sheet Music: MuseScore
Text-based music making: Lilypond
Chiptune/8-bit: Famitracker
Online Sheet Music: flat.io, Noteflight
Digital Audio Workstation (DAW): LMMS
A free and public domain library: IMSLP.org
Free, sound effects library: Zapsplat.com (You can get a paid account too and the money will be donated to charity. You will have to wait 10 seconds to download if you're using a basic account)
Easy-to-use compressor: 7zip
Add Google Chrome-style tabs to the Windows file explorer: Clover
Free, no ads and student friendly: Gwiddle
Free, has addons and elements to make setup easy: heroku
Free, easy to use cloud hosting: openshift
Free and fast hosting with no backend: GitHub Pages