Of course, there are no 3 sopranos like the 3 tenors (Carreras, Domingo & Pavarotti). Tibur Rudas created his 3 sopranos but Kallen Esperian, Kathleen Cassello, Cynthia Lawrence never really caught on as a brand.
My 3 sopranos is Montserrat Caballé, Mirella Freni & Katia Ricciarelli. All three have a connection to Josep Carreras.
Montserrat Caballé helped the young Carreras forward as she heard his voice in a little role in Gran Teatre de Liceu. I saw MC live in 2004 in a concert with José Cura.
Katia Ricciarelli was the preferred partner. They was the optimal opera couple of their time. I saw KR live as Mimi in La Boheme in 1990 in Oslo.
Then there is Mirella Freni. Josep Carreras made many opera recordings with Freni. They naturally sang many times together on stage. I saw MF live as Fedora in Zürich in 1994s
For more reviews from my travels, see www.operaduetstravel.com