The things which my kids loved at that age: wide mixture of dress up clothes (not bought kids costumes, more stuff from the attic, grown up things, wild pieces of material, etc); a small shop with till and pretend food, etc; huge varied mixture of plastic animals, wooden figures, wooden town, various odds and ends; an old fashioned wooden desk with lots of little drawers and cubbyholes (£20 at a car boot sale) which I stocked with pens, paper, empty note books, stickers, sticky notes, and lots of other school and office supplies; mixture of stuff for junk modelling, including things like old stamps and buttons, catalogues to cut up, pieces of interesting paper and fabric, as well as the usual stuff; huge oversize cardboard boxes which we made into castles, tunnels, a boat, a carriage, etc, with the help of box cutters, leftover house paint, and various decorations.
My kids never played much with the puppet theatre or dolls' house: not sure why-