Preparing the DTS classroom was so much fun! We basically were able to decorate it from scratch. Chairs, tables, or couches? Or a combination? Artwork, rugs, etc. We really wanted to make it a fun, comfortable space. A place where the students would want to hang out even when there wasn't class.
So we went with couches! Cheap and relatively comfy [not too mention slightly ugly], but not so comfortable people would fall asleep.