For the record, randall Munroe's XKCD uses this:
Creative Commons Nocommercial, any version (#CC-BY-NC)
This license does not qualify as free, because there are restrictions on
charging money for copies. We recommend you do not use this license.
And I quite like it, so I won't personally follow the FSF's recommendation
because a fully free license makes perfect sense regarding software,
but I had doubts about artistic creations for example.
Now there's no doubt in my mind anymore.
I'm finally at peace :P
at least this license is perfect for comics and similar creations.
Also, if I can run non-free programs (like games I find no replacement for)
in a TRULY sandboxed environment on my Trisquel, I won't make it a habit but
I find no harm in that
if it's fully disconnected from any data/location data etc.
But again, I personally consider that to be the exception, not the rule.
And for now, I hadn't to resort to that yet. So far, so libre.