There are really no 'standard' quilt sizes for any mattress type. You need to decide how long a drop you want, and on how many sides. Also, (just to complicate things) there are two types of twin mattresses, the mattress tops measure as follows Twin: 38 X 75 Long Twin 38 X 80.
Unless it's a surprize gift, I would contact the recipient & have them measure their mattress to see which one they have. I know that many college dorms have the long twins.