"In the Cards"
A somewhat odd choice, but to me it really encapsulates the inherent "good" of Star Trek, the hopeful future where even an enemy will kind of smile and basically say "that's cute, no worries" when faced with a positive situation.
It's my favorite Weyoun moment for sure. It adds such a depth to the character. There is truly nothing personal in anything that happens before or after. Weyoun doesn't dislike Sisko or humans. Weyoun has a job to do it, and he's going to do it to the best of his ability. But... Sisko's kid wants to give his dad a baseball card because it will make him happy? Sure kid, take the card. Have fun.