It looks like I'm the odd man out here on size but I make is what I've seen referred to as a "couch quilt" which is smaller than a bed size quilt. It is more in the line of 62-65" x 50-55" range. It is easy to snuggle up with, large enough to use on top of a bed (but not cover the whole top with overhang) for warmth and not so heavy and hard to drag around as a big quilt. It also can be most any pattern and colors as it is not going to be used as a decorator specific item like a bed quilt. It is the size that I make for gifts of any ages.
For those who are making quilts for people to take to college make sure you mark your quilts with names and labels that aren't easily removed as the communal life of college students (whether in the dorm or apartment) makes it easy for things to come up missing.