The best motetists, in my opinion: Dufay, Josquin, Gombert, in chronological order.

Check these out:

Henry's Eight did an excellent recording of that piece on one of their two Gombert albums. The album with this motet has darker works, and the other album showcases the calmer or joyful side of Gombert.

This one is from a double-CD album by Beauty Farm, full of motets by Gombert; you won't find a more profound album than this.

Cardinall's Musick did some fine recordings of William Byrd's music, including many motets. I've only heard volumes 10, 11, and 13. The seven-minute Salve Regina from vol 10 stands out for me, as do some of the darker motets from those volumes.

The album "Essential Josquin" by the Clerks is something I'd recommend. It only has a few motets though. There's an album by Orlando Consort that has a CD full of motets, probably the best choice for Josquin if motets is all you want. For some reason, there's not much available in terms of full albums devoted to Josquin's motets. You'll find some fine performances scattered across differently themed albums, but you'd have to be very dedicated to buy them only for the Josquin motets.

You may be interested in a double-CD album called "The Spy's Choirbook", which has 34 motets - many of them anonymous - from the late 15th century and early 16th century; the book was compiled in around 1516, so a few years before Josquin's death. It has some pieces by Josquin, some by the other major composer of the era Pierre de La Rue, some by the rather well-known Jean Mouton, and some others but mostly anonymous.

 

Philippe de Vitry wrote early motets.

 

I'm not really sure I know what a motet is, and I'm less keen on Beauty Farm's Gombert than chordalrock. But I can say this, I've been knocked out by the songs on this compilation CD of music by Pierre de la Rue, Alexander Agricola and Nicolas Champion

The essay in the booklet is also interesting, food for thought.

Also by the song (motet? I dunno) called O primo homo coruit on this CD

 

I'm not really sure I know what a motet is, and I'm less keen on Beauty Farm's Gombert than chordalrock.

Well, compared with masses, they gave more opportunity to express texts, but I'd say there was a long period of time during the early to mid Renaissance when motets and chansons were - as far as I can tell - the same thing but with different language.

As for the Gombert, to me there's no Gombert without the recordings by Sound and the Fury and Beauty Farm. They're so necessary for the way I see Gombert - and what I admire about his music - that it goes beyond normal differences of taste for me. I think Gombert is basically about a marriage of a certain kind of timbre to certain kind of melody that nobody else does or doesn't do half as well, with those two ensembles having that certain kind of timbre and bringing out those certain kind of melodies better than other groups (not to belittle his at times superb sense of harmony).

 

Who wrote the first motets?

The first motets came from the 1200s, apparently springing from France. Most of them are anonymous.

William Byrd's Ave Verum is remarkable for its restraint and poignancy. Notice how he staggers points of imitation, unlike Josquin or Palestrina.