Thought usually to be an English vocal genre that was popular in the Renaissance, the madrigal actually has roots in Flemish music, and going further back, appears to have been a descendant of the Italian frottola, a form noted for chordal accompaniment to a melodic line. Whatever its true origin, examples of the madrigal in all its variety can be found in music from the Netherlands, Belgium, France, Italy, and England, and they offer an ease of style and communicability that keeps them popular with vocal groups today.

For a broad collection of madrigals in three, four, and five parts, sung with energy and charm, The Book of Madrigals by the Leipzig-based ensemble Amarcord is a good place to start. Below are samples from this 2006 release from Raumklang, which presents some of the most famous madrigals.
 
Thomas Morley: Now is the month of maying
Orlande de Lassus: Bon jour et puis quelles nouvelles
Orlande de Lassus: Bon jour mon Coeur
John Dowland: Come away, come sweet love
Cipriano de Rore: Anchor che cor partire
Ludwig Senfl: Ach Eislein, liebes Eiselein
Anonymous, Scottish: Remember me, my deir
Thomas Weelkes: Since Robin Hood
Thomas Weelkes: Strike it up, tabor
Adrian Willaert: Vecchie letrose non valete niente
Heinrich Isaac: Innsbruck, ich muß dich lassen
Thomas Morley: I love, alas, I love thee
Pierre Passereau: Il est bel et bon
John Dowland: Come again, sweet love doth now invite
Hans Leo Hassler: Mein G’müt ist mir verwirret
John Bennet: Weep, O mine Eyes
Henry VIII, King of England: Pastyme with Good Companye
Adriano Banchieri: Contrapunto Bestiale
Antonio Scandello: Ein Hennlein weiss
Juan del Encina: Cucú, cucú, cucúcu
Juan del Encina: Fata la parte
Josquin Desprez: El grillo
Anonymous, Canciero de Montecassino: Dindirindin
Jacques Arcadelt: Il bianco e dolce cigno
Giovanni Giacomo Gastoldi: La bellezza
Nicolas Gombert: Triste depart
Josquin Desprez: Mille regretz
Thoinot Arbeau: Belle qui tiens ma vie
Alonso de Alba: La tricotea
Juan Vasquez: Gentil senora mia
Baldassare Donato: Chi la gagliarda
Anonymous, French: Quand je bois du vin clairet
Ludwig Senfl: Das Gläut zu Speyer