I have mine in a book cupboard which has glass doors on it (stops them from getting too dusty). Between the original 4 shelves I've added another 4 shelves made of perspex so I can display lots more smurfs. I'm starting to run out of space though so I may have to pack the houses away in the near future to make space for more smurfies.
There have been other discussions here about display cabinets & I think that Ikea has some nice ones.
I should look for a cupboard with doors unless you like dusting & washing your smurfs.