Happy Cotton Library Day

Professor Nokes, over at Unlocked Wordhoard, has announced Happy Cotton Library Day, in celebration of those manuscripts that didn't burn in the fire of 1731, and solicited our responses regarding our favorite Cotton MS. It's a hard question, actually. There are a lot of really important, and really famous ms. in the British Library's Cotton collection. You can see a complete list here, and a list of the "stars" here, a list which includes the unique-but-burned-in-the-fire ms. of Vitellius A.xv Nowell Codex, containing Beowulf and Judith, or the mss. of the major Aelfrich texts, and the only copy of the Gawain Poet's works. I'd have to say I can't really decide between Nero A.x, which contains Pearl, Sir Gawain and the Green Knight, as well as the less well known works of the same poet, Patience, and Purity/Cleanness, and Nero D.iv Lindisfarne Gospels.