I have a pihole set up with pivpn. Octoprint and a cluster of 4 pi zeros on a pi 4 to experiment with cluster computing.
Over the last few years with the raspberry pi people selling their inventory to enterprise customers instead of the hobbyists that have using them for 10+(?) Years ive found that x86 thin clients are actually a much better option in terms of price and upgradability. Most modern thin clients (wyse, HP, etc) have m.2 storage expansion, sodimm sockets, and sometimes even pcie expansion. If you get lucky you can get a decent current-ish gen thin client for ~100$ depending on the specs. What are pi 4s going for these days?
I mostly use my 3B+ as a development and sysadmin sandbox. Lately I’ve been using it to test out a few IoT-type projects.
I’d love to get my hands on a Pi Zero W at some point, but chip shortage.
I have two in use right now, one with RetroPi connected to a small tube TV in my living room (did you know that the headphone jack on the pi can also output composite video!?, I didn’t until recently).
The other I have setup on a bookshelf as a model PDP-11 (from the great PiDP-11 kit). It’s mostly just some pretty lights to look at, but it’s also a functional PDP-11 simulator. Theoretically it could also run pihole, but my router has openwrt which has the same capability.
pihole is basically it at this point. Got eonugh spare machines sitting around to do the rest anyway
One for pihole. One for Home Assistant. One for an office dashboard.
Do you really need three pis for that?
Pihole is on an old Pi 2 or 3. HA is in my network hub and attached to external storage. Office is in another building.
After my NAS suddenly stopped booting, I bought a cheap USB hard drive enclosure, plugged it into the Pi and now my Pi is a poor man’s NAS.