I started watching "Stargate: Atlantis" on DVD and stumbled across this little scene in the episode "Hide & Seek". Painted a big grin on my face:

Elizabeth Weir: [lights a candle] Teyla told the Athosian children that lighting a candle will protect them.
Rodney McKay: And you're doing it because?
Elizabeth Weir: It's gonna get dark in here.
Rodney McKay: Huh.
[presses the button on his MaxaBeam]
[smiling] Huh, huh.