I also have the Pimoroni Enviro+ in my living room. I've got their Grow kit somewhere as well, but... no plants since I moved.
I used to have a Kubernetes cluster running on some Pi3's, but they got a little too slow and I was bumping up against the lower memory. Lots of other self-hosted stuff, but it's all on some old off-lease computers I found cheap, not on a Pi.
the home assistant one runs a reverse proxy and adguard/tailscale docker among other things.
they're useful but the price point sucks right now unless you absolutely need the IO ports/shields they provide. I have a PoE shield on my home assistant one that makes the installation very tidy.
retropie - pi3b+
gps based ntp (2x pi2 + gps hats. Chrony rocks.)
rtl_433 monitor for 915 and another for 433 (2x pi2, 2x rtl-sdr sticks)
an ads-b 1090 monitor (pi3 + rtl-sdr stick)
libreelec - plex clients (2x pi4 (1GB and 2GB)
an emulated macintosh (pi3)
a flood monitor in the basement (pi1)
an aarch64 dev platform (cm4-8GB) and another (pi5-8GB)