Whonix and Qubes are somewhat similar, the primary difference being that Whonix focuses on isolating Tor and the web browser whereas Qubes focuses on isolating everything. They both use virtualization to achieve isolation and they both offer strong protection from hackers deanonymizing you by pwning your browser. Qubes just has a much broader focus. I would suggest giving Qubes a try, but if you find that it is not suited to your needs, or if you find it too difficult to use, Whonix is a solid alternative. For the most part I would strongly suggest using either Whonix or Qubes over using something like Liberte or Tails. But you do need to keep in mind that the focus is different. Tails: Focus is on not leaving any forensically recoverable traces, being highly portable, best suited to people who use a wide variety of wireless access points. Keep in mind that if you opt to use persistence, then you are not fully protecting yourself from leaving forensically recoverable traces. I find persistence to be almost contradictory to the original goal of Tails, making it more similar to Liberte now (although I think Liberte at least supports persistent entry guards). Liberte: Focus is on being a portable light weight OS oriented towards simplicity of use and basic security. This is what the focus of Tails seems to have shifted toward as well, at least when it is used with persistence.  Qubes: Focus is on protecting yourself from hackers and providing very strong security via user defined and potentially very intricate virtualization based isolation policies. This can be utilized to encompass all of the security goals of Whonix and more. Whonix: Focus is on protecting yourself from hackers and providing very strong security via virtualization based isolation of Tor and your browser. The primary focus is to protect your IP address from hackers, although isolation of your browser will also protect your private keys / plaintexts provided that you encrypt with GPG on the host. For the most part Whonix is probably adequate for most of the people here, Qubes is definitely a lot more capable but Whonix does address the primary concerns.