Last year I downsized from an old HP tower server with a xeon, and 8x 1tb SAS HDDs, to a single Intel NUC with i5 and 4x 4TB SATA HDDs.
I run Proxmox on it, with several VMs.
- Gerbera - DLNA/Upnp server for streaming my media
- Shinobi - monitors and records my security cameras
- Syncthing - for keeping backups of important things from my laptop and my phone and my wife's phone.
- A container with a Python script that is constantly monitoring my solar panel energy production and sends it to pvoutput.org
- Some VMs with different versions of Centos and PHP for developing and testing webapps on.
I also have a raspberry pi with home assistant and a ZigBee USB adapter, for controlling the lighting in my house.