Photoshop
The best tutorial video for using...
- Adjustment layers is this
because it's clear and concise (about 6 min long), while still giving in-depth and understandable explanations.
- The clone stamp tool is this because it's
super comprehensive, explains everything in detail, and walks you through multiple examples.
After Effects
The best tutorial video for using...
- Keyframes is this because it's quick and to the point (about 4 min),
and it shows how to use keyframes with position, scale, and opacity.
- The 3D camera tool is this because it walks you through the process nicely
and explains solutions to some problems you may encounter.
Illustrator
The best tutorial video for using...
- The stylize panel is this
because it walks you through using all of the effects on the stylize panel found under the effects dropdown menu.
This is a longer video (about 15 min), so you might want to skip around to the parts you want.
- The eyedropper tool is this
because it's quick (less than 4 min), but covers the main things you need to know.