THis volume has largely been superseded by The Romance of Arthur, New, Expanded Edition: An Anthology of Medieval Texts in Translation, but if you can get a copy (it will have to be a used copy), it contains a number of texts not in the other anthology: the Welsh "Peredur" (a confusing version of the Grail story), the "Lay of Graelent" (a version of Marie de France's "Lanval," which isn't Arthurian in setting, but provides some interesting details), and "Yvain" by Chretien de Troyes.