I wonder why thread like this is missing here.
So what is your favourite opera overture/prelude?
Please don't discuss about your favourite operas in this thread, but really about opera overtures. It can be considered as a separate work and often is performed in this manner. Excellent overture can introduce poor opera and and excellent opera can starts with poor overture.
My favourites are:
Marriage of Figaro
Ruslan and Ludmilla
La forza del destino (there are two versions I think)
Pelleas et Melisande
The Cunning Little Vixen