My favourite flashback... probably the DL6 incident; it's pretty sad for Edgeworth. =( Plus, it sort of helped set up the story for the Fey family feud arc.
BTW, 45 days until Professor Layton vs Ace Attorney comes out in Japan! Not sure if I want to ship it though, haha~
Mind if I ask a side question:
If you can pick one thing from Ace Attorney that excited you the most, what would it be?
Well fior me generally, it's whenever there's a cross-examination, and when that traditional "OBJECTION!" occurs, it's followed up by the cornered music. :3