I think some of the best lines have come from changing characters' names in Final Fantasy games.
In FF7, if you rename Barret "Mr. T" (which I'm sure most, if not all, of you did) then you get gems like:
Aeris: Thank you Mister Mr. T
Barret: Don't call me Mister Mr. T. That don't sound right.
Or in FF8, one of the board members back in the day renamed Griever to "YourAss" so then Ultimecia would say "I shall now junction myself unto YourAss."
And I know someone here must've renamed Squall to Emo Kid in FF8 and laughed when Emo Kid says "I'm more complex than you think" to Quistis.
In FF9, I just had to rename Amarant to F4G0T (the aforementioned board member renamed Cloud that in FF7 to seek funny lines) just so he could introduce himself as "the Flaming F4G0T." And later on it was funny seeing Eiko say "F4G0T, are you being a bully again?"