<p>I have used PLA and PLA+ so far and I know that it can use ABS and PETG but I'm curious what other materials could I in theory use with my Ender 3?</p>
<p>It is a stock configuration, for the time being at least until after Christmas, and my grandfather and I have designed an enclosure to build together.</p>

Consider
Wood PLA
.  It is similar to PLA but more abrasive, and with different happy-temperatures.
Especially useful if you want to paint your output, or if you have woodworking skills/tools then prints can be (somewhat) worked and incorporated into larger projects.
Imagine printing detailed
scallions
or
crenellations
or
gargoyles
for a spooky dollhouse - the main walls would use an inordinate amount of filament whereas sheet-wood is cheaper.