The fight
Let's talk about a fight that isn't Anakin and OB!.
What do you think propells Ani to either kill or hurt Padme? I think he kills her, but some may not agree. Either way though, something must happen to strain their relationship, and so far we don't know exactly what that is.
My theory:
Padme notices the change in Anakin. In order to find out what is up, she programs R2 to "spy" on him.
R2 then discovers Anakin's double life and his secret relationship with Palpatine.
They get into a big argument over it, and in the heat of the moment Padme accuses Anakin of having an affair with Palps. So Anakin strangles her in a fit of rage.
OK. Maybe not the affair part, cuz that ain't believable. Padme is too hot for her hubby to go poofter, but you get the idea.
Any thoughts?