Black Knight, bought in 1998. It was my first pin, and I bought it the year my only son was born.
When my son was younger, he said we ought to sell it because he liked the newer games better. But around the age of 12 he decided that it had strong sentimental value for him, because he grew up with it. He's 17 now, and he'd be really upset if I sold it. Same with LOTR, but only because he has the GC on it.