I leave the next person an arcane nostrum. First, consume it and then watch this:

Dreams of Dali

I leave some of my happiness from watching the above for the next person.

(I loved some things like: the towers reminded me of the one scene of the first Neverending Story, the striding animals reminded me of the transports from Morrowwind, etc)

I leave a key to CD Projekt's secret stash.

*I open the stash and leave some goodies for the next person who posts here.*

Half this pizza has a topping I'm not familiar with so I leave it here, but the half I keep for myself is 3-meat and in excellent condition.

I collected some of the anchovies, sardines and pineapple chunks people tried to decorate my pizza with, yesterday.
I leave that stuff on the already odd-looking half of a pizza MichaelD.965 left here. That will teach 'em... Yeah!

*I take all of that disgusting stuff, adjust my recipe and bake it into small cups of exquisite-looking quiche for the next poster* Bon Appétit

I add anchovies and pass the - um - ostensibly exquisite stuff on to the next user, along with a good purgative.

I take everything because what doesn't kill me, makes me stronger. This won't kill me. We'll see...
Meanwhile I leave a Pandora's box. I don't know what's in it. Do you want to know?

I take the Pandora's Box, open it and find hope which is more than I had before...

The next one gets a sense of humour from me.

I like senses of humor

Person below gets... a digital hug?

(accepts the virtual hug)

*leaves a $100.00 chip to a famous Las Vegas casino*
(the name of the casino is on the chip, so I don't need to mention it)

picks up chip and eats it

Leaves a water gun for person below, full of red dyed water ofc

I grab the water gun and empty it into a punch bowl.
It does really look like punch, so I throw a ton of sugar into it and some pineapple chunks that are still lying around.
I leave the "punch" and take the water gun to another thread...

I also leave a sign: "Now I Have A Water Gun Ho-Ho-Ho"

I discreetly dispose of the 'punch' on the soggy grass on a rainy day, and leave the bowl empty for the next poster save for those bits of pineapple, weeded from a pepperoni pizza long forgotten.