[stock_toaster]

Might be worth looking into QubesOS[1]. It uses Xen to compartmentalize things. Never used it myself though.

[1]: https://en.wikipedia.org/wiki/Qubes_OS

[Ojamaflip]

I often go back and give Qubes_OS a try but then it lets me down with USB passthrough for a lot of devices I need - not least a USB tethered Internet connection (or USB Networking). It just is so complicated that I gave up and I'll look again when they get to version 4.