Stamps from Ireland with their cute little monks on them
The Australian stamp with the Three Wise Men from 1959, proving once again that all things were better when my parents were growing up.
The Hommes Abby (Abbye aux Hommes), Caen, Normandy. Classic example of Romanesque architecture (and a personal fave stamp of this gal who's absolute top 10 fave buildings she visited includes the Koln Dom.)
And a stamp that still holds as much truth today as it did back when first class postage only set you back 5 cents.