One of the best is episode 33 I think:
*Izumi bursts through door*
Greed: And who are you?
Izumi: PISSED OFF!
Izumi to Al: You're in for a long lecture later so you better get ready!
Al: *tears* I-I'm sorry!
*Ed bursts through door*
Ed to Greed: Put her down, and let Al go! (etc.)
Greed in the background: Hey, I have a hostage here. Anyone forgetting that?