My brother and his wife got me a raspberry pi for my birthday :D
So far I haven’t decided what to do with it, But I have lots of ideas – I could turn it into a gameboy (though I already have a couple of handheld retro gaming machines – I have a jxd 5110b handheld android thing, so I don’t know that I need another) or even a mini arcade machine like the one in this video…

I could install kali and turn it into a super-powered wifi pineapple or I could use the raspberry pi to control a 3d printer (I’d have to get a 3d printer too)

A slight update, I have turned my raspberry PI into a SNES using retroPI

RetroPie allows you to turn your Raspberry Pi into a retro-gaming machine. It builds upon Raspbian, EmulationStation, RetroArch and many other projects to enable you to play your favourite Arcade, home-console, and classic PC games with the minimum set-up. For power users it also provides a large variety of configuration tools to customise the system as you want.

I have also turned my raspberry PI into an adblocker that blocks adverts on my whole network using PIHole

https://www.youtube.com/watch?v=9Eti3xibiho

The Pi-hole can block ads for all devices on your network. All you need is a Raspberry Pi connected to your router. It was inspired as a low-cost, open source alternative to the AdTrap. The Pi-hole works on the the B, B+ and Pi 2 (it can also run on the Zero, but you need a micro-USB-to-Ethernet adapter)