Ennio Morricone wrote a lot of soundtracks. This post wants to be a note about the ones which maybe aren't that famous outside Italy, but which are still worth being listened, at least in my opinion (other users are free to add other works to my list). So I will not mention anything he wrote for Sergio Leone's movies or for other famous ones like "The Untouchables", "Mission", or "The Hateful Eight" (although I will mention previous works which have been re-used in Tarantino's movies).

Talking about spaghetti westerns, a piece I enjoy is this one:

"L'arena" (from Sergio Corbucci's "Il mercenario" - later re-used in "Kill Bill vol.2")

There are a couple of comedy westerns in which Morricone played with classical music and inserted some famous pieces into his works:

"Cavalcata... per Elisa" (from Damiano Damiani's "Un genio, due compari e un pollo")

"Mucchio selvaggio" (from Tonino Valerii's "Il mio nome è nessuno" - a nice movie starring Henry Fonda)

Switching to other genres, I remember of another soundtrack which is whistled, written for Carlo Verdone's comedy "Un sacco bello":

Other soundtracks I like:

"Scuola di ballo al sole" (from Pasolini's "Uccellacci e uccellini" - to me it sounds very surf-rock :)

"Romanzo" (from Bertolucci's "Novecento"):

"Rabbia e tarantella" (from Paolo and Vittorio Taviani's "Allonsanfán" - re-used for the closing credits of "Inglorious Basterds"):

Morricone also wrote the music of some songs. One very famous in Italy (which wasn't written to be a soundtrack) is:

Mina - Se telefonando

Another one, feat. Joan Baez, was written for Giuliano Montaldo's "Sacco e Vanzetti":

"Cinema Paradiso" is a movie which I've mentioned countless times in the past, and which is quite famous, so this could be seen as an exception to the rule. Anyway you can test your knowledge of modern movies in this tribute the Simpsons dedicated to it :)