My father has a "Maria Moliner", its a good one but VERY BIG.
It's a USAGE dictionary, gives examples and more information than a usual one.
It's a VERY good Christmas gift.
it's the first one here
http://www.amazon.com/s/ref=nb_ss_b?...=Maria+Moliner
About 1500 page each volume, and expensive (295 dolars)
It's cheaper in Spain, for example (162 dolars)
http://www.casadellibro.com/libro-di.../2900001200033
but you need to have free place in your package.
Saludos
PD: Look, in barnes & Noble you have a good price (152 $)
http://search.barnesandnoble.com/Dic...4928865/?itm=1
If you REALLY want it (as sayed, it's expensive) it's better to buy it there online.
Due to the price, it's considered the dictionary for sybarites.