I own a T-shirt with a graffiti of chemical reactions! Also dictionary collection, a couple dozen books including several languages I've made basically no attempt to learn :P
I wouldn't call it the geekiest, but there are only a few things in life, that get me as excited as my library of Steam games does.

Even though I don't play as much as I used to in a previous life, I am constantly on the lookout for new games, especially the indie ones; and I keep getting new ones every month, constantly; thanks to my Humble Monthly subscription.
Looking forward to playing this game called Night in the Woods.

It was my college (Second year) hostel. I purchased a P4 system from local vendors for 3K. We install GTA, NFS, poker and other small games and a lot of movies ;) as well. One day at around 02:00 am, it got shut down automatically and did not start again :(. And we were watching "Van Helsing" movie at that time. We picked a knife from Hostel canteen and open cabinet of the system (First time we see the internal part of a computer). We saw the on/off button to become black, so we cut the wire of the power button. But as you know computer on/off state is only one time signal, which can start or shut down the computer. So we can't bind both wires. We can send only signals. So, we decided we will uproot our hostel warden office's door bell plug. I successfully convinced my friends. And after 30 minutes we were there. We uproot the doorbell button. And connect it to our computer. That was our geekiest thing I have done.
Next morning our hostel warden came up to our room and gave punishment of 1K and send a letter to parents.
Comment below how hostel warden know that we uproot his doorbell button......
Well what I do as geekiest to me is that I actually borrow many of the books related to computer science from my university (which sometimes i don't read).
Sometimes the Setup folder (which contains all the tutorials etc) exceeds the size of the Movie folder which I have on the same PC

(tutorial folder)

(Movie folder)
That is my geekiest thing which I still owned :)
PS: I have hided the locations so that you can't use my Movies and Tutorials for free :D
A windows virtual machine full of computer viruses which I used to call the piranha tank. I don't have it anymore unfortunately :-|
Engineering an eGovernance Product | Hashnode Alumnus | I love pixel art
Richard Onsman
Full stack developer
If you consider this to be geeky 😁 😉
My old hand held video game console.