After being involved in the IT field for nearly 30 years, my strategy at home consists of using 2 primary machines as follows.
The machine I use for hosting the bulk of my files (essentially, being used as little more than a simple NAS) is running off of one of Intel's first Atom CPUs and Windows 7 on 2GB of RAM. The CPU's ridiculously slow, but for serving files (music, video, pictures, installer ISOs), it's more than adequate and a faster CPU wouldn't buy me anything. The machine has no video card, so if I need to do anything with it that goes beyond file shares, I use RDP. The machine has 4 hot-swappable drives accessible from the front and the whole thing barely registers at 45 watts, so even my cheap UPS can keep things going for almost an hour.
Other than the OS and a few file shares configured, there's no software installed on it, so I don't bother backing up the OS--it's just as fast to reinstall it from scratch than it would be to restore from a backup.
All of the data files (a partition separate from the OS) are backed up regularly on a pair of external 4TB drives that I rotate once a month (I bring one to the office and bring the previous month's back home). That takes care of both offline and off-site storage. The drive I have at home is only connected and powered on when updating the backup.
My one beefy machine has an i7 CPU and 32GB of RAM, and hosts a multitude of virtual machines (anything from XP to Server 2012 R2 and a number of Linux flavors to play with). Again, the host OS has nothing installed on it so it doesn't get backed up. The host is running Server 2008 R2, but the free Hyper-V server would do just fine if you're ok with going through the initial configuration from its PowerShell menus--as with the NAS, I hardly ever need to do anything with the host OS.
The virtual machines are what I do all my work on. Instead of backing up individual OSes and the software installed on each, I just back up each virtual machine's virtual hard disk (.VHD) file. Backing up and restoring entire machines (OS, software and configuration included) becomes a simple matter of copying files around from one location to another. The host machine has only 2TB of storage, but it's plenty for all of the VMs--all the large, bulky data files (VHDs excluded) are on the Atom machine.
The external 4TB drives I use in rotation are large enough to include the backups of both the VMs and the NAS.
I use RDP extensively. I can access/work with all of my virtual machines, as well as the files on the NAS, from any number of other desktop machines, laptops, my Surface and Android tablets, media player (hooked up to my projector), etc.