[parmezan]

YubiKeys! https://www.yubico.com/ a tool to increase your security. But can be expensive.

His/her favourite programming language or tool as a mug/sticker/tshirt on redbubble.com

Some cool mug that automatically warms up or stirs with a button. Because techies need coffee.

Laptop webcam blocker sticker/shuffle to keep ur privacy.

LED stuff. Like a led strip or something because cool lights are nice.

Smarthome stuff like a smart plug! It shows power usage of devices and u can program it using automations with homeassistant https://www.tp-link.com/en/home-networking/smart-plug/hs110/ - cool to automate ur home with it.

[fsflover]

Librem Key is a FLOSS alternative: https://puri.sm/products/librem-key.

[riedel]

Happy with solo keys (also open source and hackable)

[gruez]

doesn't support FIDO/U2F though?

[cgranier]

+1 for the YubiKeys. Can't really have too many.