My two have a playroom and I love it :-). Mind, I only allow one trofast single depth box of tat (that gets regularly cleared out as they forget about it)
The rest is actual 'things' - I'm in there now (it is also the dining room so is the biggest room in the house - I get to keep my love,y front room tidy as we hang out and do homeschool in the playroom)
Starting at the gas fire...high up resources cupboard (arts and crafts, board games, education packs, workbooks) bookshelves, dressing up, armchairs, little table and chairs, unit holding paper and pens, lego, trains, cars, musical instruments, dolls, toy kitchen, farm, fridge (with magnetic poetry) easel then a road mat on the floor and educational charts on the wall. Its like a little nursery, and most of it is wooden or good quality plastic and second hand. I try and ban electronic toys and take the batteries out of most gifts. All in labelled trofast so it can be found and tidied easilly.
The DDs have friends round and they all play nicely in the playroom and me and the parents can sit in the front room and chat.
It is a pretty small house, but I don't allow playing in the bedroom and only one toy each and no rowdyness in the front room so the playroom lets them have totally child focused space and also keeps it contained. Bedroom has beds and clothes in, a couple of teddies on each level of the bunk bed and that is it.
I'm poor, but I don't really have expensive hobbies - just playing music, drinking tea and reading books - so I can spend £50 or so on secondhand birthday and xmas presents and get nice stuff.