I've tried various home setups in the past but the one I've currently settled on which has worked the best for me is the following:
I have a central NetGear ReadyNAS box with 4 x 1TB disks raided to give 2.7TB worth of storage and redundancy.
For media content I use a Mac with iTunes pointing all content to the NAS box. I use iTunes to centrally manage all media and serve it up to two Apple TV devices. iTunes on Mac is pretty good software and I've not found the same seemless experience with any other product out there.
I have two low end Dell Poweredge servers, one for a domain controller and web server and one for public facing TFS and SharePoint 2010, that I use for work.
Backup of my work Dell Laptop is done with Windows backup, which takes all my Documents folder and creates a system image every night and plonks it on the NAS drive.
I have a Time Machine drive for backup of the Mac also.
Every important bit of data is stored on the Raided NAS drive which gives me some comfort, the only thing missing at the moment is off site backup which I need to sort out. Problem is I have around 2TB of data on the NAS drive that ideally I would need backed up.