My DD is now five, but when she was two I asked her grandparents to get her an easel (the kind with chalkboard on one side and dry erase on the other and a contraption for hanging rolls of paper). It was the single best thing they could have ever gotten. That kid has used it so much. It stands right in our living room (we live in an apartment) and she'll spend hours sitting there doodling, painting, etc.).
The second best thing (and this qualifies as furniture rather than toy) was a small table and chairs. She has used that for four years now, every day, for tea parties, drawing, playdoh, etc. (I also asked her grandparents to purchase that, as they insisted that they don't have any ideas for toys or what she needs, which is fine with me).
Other hits are her puppets, a hair styling head, legos and tinkertoys.