final say

China's final warning

A warning that carries no real consequences; an empty threat.

final cut

In the movie industry, the final released version of a film.

final nail in the coffin

Something that is ultimately responsible for a previously prospective demise or failure.

have a say

To (receive the opportunity to) voice one's opinion.

I'd say

It is my estimate or opinion.

I'll say

Used to indicate emphatic agreement

let's not and say we did

Indicates that the speaker does not agree with a proposed action, and does not wish to participate.

needless to say

Clearly, obviously.