'most prized' is correct and usable in written English.
You can use it to describe something that is highly valued. For example, "His most prized possession was the gold watch he received from his grandfather."
Data centers are among utilities' most prized customers.
The six-hit is the I.P.L.'s most prized achievement.
It is one of the most prized of British sports.
The invitations are among the most prized in Washington.
He has since joined the elite ranks of the United States' most prized and dependable soccer export.
Companies have long used Oracle's software to keep track of their most prized information.
And the assets most prized at the company are brains and data.
My most prized souvenir is a piece of origami from Japan.
OYSTERS The most prized Gulf Coast oysters come from Apalachicola, 90 minutes south of Tallahassee.
America's most prized journalistic possessions are suddenly looking like corporate millstones.
But as O'Toole pointed out, Inkster's most prized accessories are her children.
