Haha, thanks all!
Some highlights:
I got my dad a "For A Little Girl Who's Five" - he was really confused and thought he got the wrong card. But it was later displayed proudly among the lighthouse and boat-themed card mantle.
I also got him a card for something "From The Prime Minister of Israel" all written in Hebrew inside. No one knows what it said.
For Mother's Day one year I got my mom a "Congratulations on Becoming an American Citzen" card. The inside was apropos because it mentioned that hard work paid off, and moms are hard workers.
I won't recommend doing this for anyone...there are sadly some people in this world with no sense of humor!