Depends the OS.

Windows its Space

On Linux shift since space will fill in the password field with spaces

my computer doesnt go to sleep.

It must stay awake, at all times, awaiting my input.

Any key

Escape is kinda hardcoded as a safe button in my headspace and spacebar is just fun to press.

I'm a mad man I click different shit every time.

The power button. I've disabled usb-wake because my wireless mouse keeps waking up my computer

Esc like 3-5 times (to also prompt the login input) or mouse wiggle

I hit the "wake on lan" icon on my phone, since my computer is in a different room from my monitor and the usb doesn't work for waking it up directly. But if I could, left ctrl all day!

I plop my furry balls menacingly on the keyboard and inevitably hit at least half the keys

Caps lock because it doesn't do anything like enter or other keys might do and if I see the light blink then I know that the computer/keyboard is not frozen.

Space. On my mechanical keyboard it makes a nice thunk. You really know you've pressed it.

i rapidly press as many keys as i can within a 1 second time frame

or i just slam the enter key a few times

I push the power button on the tower.

I just stare at it loathfully until it wakes up out of shame.

(Or maybe it's my enraged vibrations transferring to the mouse through the table and causing it to move, same difference.)

Left arrow up arrow right arrow. over and over and over again until the computer comes up

I have a BLE keyboard and a BLE trackball, so they lose connection when PC is sleeping. To wake it up I press the power button

I press my whole hand into the keyboard hitting like 20 keys probably

My PC dual functions as a server so it never sleeps

Backspace

I always hit an arrow key. Just in case it's not actually asleep but just turned off the display, and I don't want to accidentally start typing into something without seeing the screen yet. It's like, 99% unsubstantiated paranoia, admittedly.

My desktop pc doesn't wake up from keyboard inputs, so the power button. On my laptop I just open the lid.

I honestly just kind of flop my hand around on the keyboard

Power. I'm weird like that, I guess.

I smash the arrow keys like I’m playing a synthesizer.

Mouse click gang

Sleep? I run Linux. It's on. Or it's off. So power? I guess?

Ctrl to wake the screen, system set to never sleep. Stupid Plex running on Windows addiction.