I definitely agree that if you're going to go with five movies, you should go with the top ones (well, IMO) from each of the multi-picture Bonds' catalogues.
Connery: Goldfinger (not my favorite of his, but it's the definitive Bond movie)
Moore: For Your Eyes Only
Dalton: The Living Daylights
Then I'd go with CR over OHMSS since it's designed to bring in new people, free of past Bond continuity.
EDIT: Oh, you already started. Bah, I'm slow.
Good choice with GoldenEye, though.