Use the exclamation point to shout. And don't shout much at all in expository writing. Let your prose show your emphasis:
The Supreme Court flatly ruled against us! When 911 took the call, the operator said, "I'm on a break now"!
Exclamation Points with Quotation Marks
Put the exclamation point inside ending quotation marks if the shout belongs to the quoted source. Put it outside if the shout belongs to the writer:
Inside When the Shout Belongs to the Source
The man cried out: "Fire! There's a fire! Call 911!" (An ending exclamation point that is part of the quotation goes inside the ending quotation marks. No additional punctuation is necessary to end the sentence.)
Outside When the Shout Belongs to the Writer
When 911 took the call, the operator said, "I'm on a break now"! (Exclamation point showing the writer's exclamation goes outside the ending quotation marks.)