Gary Penkala has an excellent article at the CanticaNOVA site on core hymnody, listing 150 ecumenical hymns and a list of 35 additional hymns (in English) that every Catholic should know. Notice that these are hymns that every Catholic should know and not "greatest hits". Those are two different things, you see. Even Christmas carols (the assumed "gimmies") made the cut on these lists.
Kudos as usual Gary!