What OS are you and others using? I'd love to use Windows Server as it's an area I know little about but the cost of it is quite a bit
My RPi2 is going to be set up as the Plex client to play stuff on the telly.
Running the latest Ubuntu desktop release (I like a pretty GUI) but was definitely tempted by Windows, but the cost of the OS kind of goes against the idea of a cheap home server, plus the amount of open source stuff (Pi-Hole and Transmission are two lovely little low resource programmes which are just so damn useful) available for Linux makes it the better choice