With posts like this one I only hope I am saving some teachers time on the internet. I teach at the elementary level, so the songs I choose are basic and sometimes with little vocabulary. Here are my top choices:
El Día del Amor y la Amistad by Music with Sara (Bilingual)
Un amigo me enseño by Baby Radio
Los Corazones Amigos by César García
Corazón de melón by "Valentina y los valientes"
Nuestra Amistad by Plim Plim
Te Quiero by Barney