Esc, t, or I move the mouse. Depends on my goal when I'm waking it up.

The power button

SPACE bar

If there is a pin set, decimal on the numpad, else Ctrl or ESC.

Am I the only one that just kind throws my hand on the keyboard and what happens happens?

The first letter of my password.

Right arrow. Wake on mouse disabled because cats. Right arrow is on the bottom right corner and convenient to hit when pulling the keyboard tray out.

I just open it.

I use a arrow key, usually the arrow to the right

Ctrl+Alt+delete for my work computer so I can go straight to password input.
Space for my home computer.

I giggle the mouse.

I slap the spacebar, often multiple times if I'm impatient

I thump my water bottle down on the desk just hard enough to make my mouse trigger and wake up the PC. By the time I'm sat comfortably it's awaiting a password :]

Win/Super key

I find that pretty safe.

I mash the keyboard. It wakes.

Control. I'm mildly paranoid any other key will actually go through and type/do something.

Arrow up. Multiple times.

F3, what else?

I also use Ctrl, or I waggle my mouse to wake both it and my PC (it's wireless).

None! And the sucker still wakes up all the time.