The discoverability is there, but not in the wild of the OS; it's in the Settings panel. Better yet, it's configurable (and powerful).

    Settings > Keyboard > Shortcuts > Keyboard

Ditto that for the touchpad (including animated examples)

    Settings > Trackpad > ...

Perhaps we as power users are just used to not having to visit these locations?

Those are actually precisely where I discovered a bunch of OSX's shortcuts. I think this was around the time I configured the two finger right click to make playing Minecraft without an external mouse feasible.

To this day, I have not figured out how to switch to another desktop on my Macbook Air using a keyboard shortcut. To be fair, I use it very rarely.

I'm pretty sure the default is Ctrl+Left and Ctrl+Right, but I've customized it so many times I can't be completely sure.

OS X actually allows a lot of customization. You assign a keyboard shortcut to any menu item in System Preferences -> Keyboard -> Shortcuts -> App Shortcuts.

Control-Left|Right Arrow.

Gotta try it when I bring it out next. Thanks!

It's amazing how buried some of these are. Nothing tops print screen for me - Cmd + shift + 3 for the whole screen or Cmd + shift + 4 for the selection option...

My absolute favorite is cmd + shift + 3 - release - space to take a shot of a single window. Maybe it's the release part between 3 buttons and pressing space, but that shortcut is always wired to use for me.

I didn't knew this one, it's awesome, but it's with 4 instead of 3 :)