I'm not a really fan of spanish cinema but I can say some recommendations.
- The Best's Day: A film directed by Álex de la Iglesia and casted by Álex Angulo and Santiago Segura tells the history based on the diamond coming to Earth.
- In The Other Side Of The Bed casted by Paz Vega it's a funny comedy.
- The Others and The Boarding School are horror films. They're can be similars but I recommend to watch both.
- Open The Eyes directed by Alejandro Amenabar and casted by Penelope Cruz and Eduardo Noriega. There's a remake casted by Penelope Cruz too but with Tom Cruise and Cameroon Diaz. The name of the remake is Vanilla Sky. It's a science-fiction film. I prefer the spanish version.