To be fair Shanghai I think Fellatio wins the thread (am childishly sniggering at that sentence).
I agree with NormantheForeman because we still haven't resolved the PLAYROOM issue. There is no other appropriate name as far as I can see.
Should we call it the "children's sitting room"? The toy store room? "The room in which all the toys are kept and the children play but most definitely isn't a playroom because that would be poncey" doesn't exactly roll off the tongue but may appeal to some?