Something odd here.

[Bloodsword83]

Naga isn't a villain. =P She's just a rival that's usually teased. Of course, I like Naga, but I don't like Shantotto....

Besides, Laharl and MidBoss from Disgaea has that laugh also, and they're male. (As is Kefka.)

I think Laharl's laugh is in a different class. His is kinda fast during it's execution (it has to be, but that isn't the point.) where as Naga's and Dr. Shantotto's laugh is kind of drawn out, if that makes any sense.

[Shigunetheseraph]

I saw both vids of them before. THEY ARE THE SAME PRACTICALLY :P

[gabrieltim]

I just have to say if everyone in japan laughs like that im alredy there

[Shigunetheseraph]

Hmmm, here may be the kicker...
if they were both voiced by Megumi Hayashibara.