1x Raspberry Pi 3 running Home Assistant with a Z-Wave USB Dongle (Home Automation)
1x Raspberry Pi 3 running OctoPrint (Host/remote-control for 3D Printer)
1x Raspberry Pi 3 running FullPageOS (Full-screen Chromium in kiosk mode) displaying a server statusboard in our home office
Next project: 1x Raspberry Pi Zero W to run Unifi Controller
I have a couple of original Model B+ sitting around unused right now - just not powerful enough for any of the above projects.
(Update: Formatting)