A journal. (or several, in case the disaster runs long) Great to simply record the day's thoughts. It can be a great stress reliever, and is for many people. It is also good to keep a running account of the disaster in progress, your actions pertaining to it, and the daily outlook for everything. Might even turn it into a book about the event when things get back to normal. Or even a movie. (if it is the kind of situation that does allow humanity to go back to normal).
In a like manner, a set of notebooks with plenty of pencils, to take notes in one and start whatever kind of story you like to read. If you can keep an inexpensive laptop with plenty of thumb drives, or even a tablet with an OTG dongle to connect thumb drives and a Bluetooth keyboard and mouse set you can do it electronically.
Something I am amazed I did not think of earlier is a karaoke machine and plenty of song disks. Assuming you can keep the power on, or have a way to keep a few 12v batteries charged and an inverter large enough to power the karaoke machine and one or two low-power-draw flat-screen monitors. Some systems will accept thumb drives with karaoke songs.
Alternative, one of the large screen phones no longer in use, or a tablet, can have karaoke software downloaded, and all the karaoke songs you want, free. Even more if you pay for some of the newest stuff. Microphones are much better than just your voice, as the karaoke machines have the ability to add the effects that professional singers use to get the most out of their voice. Even some of the computer software can do that. And with Bluetooth microphones you are good to go. I use Trikaraoke software on my computer and have several thousand karaoke songs I downloaded from online for free, without violating any copyrights. (I will not bootleg, since I am an author myself, and sure would not want people downloading my books without paying for them or getting my permission.)
Those with instruments that do not want to sing can play along. If you get one of the karaoke machines that has instrument inputs then you can really have what amounts to a real band, with the best singers doing their thing even if they do not know the words of a song from memory.
Sigh. I miss karaoke. I have not been in several years.
Anyway, just my opinion.