Class parties are important - even in an incredibly fast paced Calculus 12 class :)
My lovely Grade 12's have convinced me that rather than continue the absolutely riveting discussion on implicit differentiation we started, for our last class before Christmas we're going to play Sporcle, and I promised to make muffins.
Thus, it should be an entertaining time before the holidays.
On a more serious note, I do think that there needs to be mental health breaks once in a while - I can do exactly 3 report cards before my head explodes and I need to spend some time distracting myself! I tend to let students take some breaks in class as well, assuming they've been giving the work an honest effort.
The nice thing about Sporcle is that it tends to require at least a little bit of mental capacity or recall ability, if only for inane trivia or Disney characters.