I'm a big fan of the Web Gallery of Art and stumbled across this wonderful German woodcut from an Ars Moriendi (Art of Dying) book of the 15th Century. (Click on the picture itself for enlargement). I recognize Ss Catherine of Alexandria (with sword and wheel) and St Stephen (in the Deacon's dalmatic holding stones). I suspect that the female saint holding the tower with three windows is St. Barbara. (One window for each person of the Blessed Trinity). The portly saint at the back is a mystery to me, and nor am I entirely clear what God the Father is doing with some rather scarly looking surgeon's implements. A nice touch is the fact that St. Michael has vanguished the demons who cower under the bed.
Also worth a look is the Internet Biblia Pauperum. The site is incomplete and doesn't seem to have been updated recently, but its worth a look to see some more gorgeous woodcuts and some interesting typological connections between the Old and New Testaments. (Hold your pointer over the Latin text for an English translation.)
To finish with, one of my favourite pictures in Rome, the Galleria Doria Pamphilj's Rest on the Flight Into Egypt. I really like his depiction of St.Joseph holding the musical score for the angel and the tender (but unidealized) way in which the Virgin Mary holds the Child Jesus. (Incidentally, the musical score is genuine - the tune is playable)