From: Rendlesham, Suffolk
CV: Midway - all the utility of an Essex, but with an armoured deck. As a testament to their good design they served for 50 years in their original Navy.
Sub: Type XXI - revolutionary. Designed for mass production with advanced features that shaped submarines for the future.
DD: Fletcher - big, capable and designed for ease of construction.
I am still pondering for the other categories...
Edit BB: Iowa. Big, beautiful and capable of taking on any other battleship in the world. The end of the BB era is not the only reason they were not replaced... (I like Vanguard, but she was designed only to use up some spare guns, so does not really count...)
For the Cruiser I am going for Brooklyn. She was a Heavy Cruiser with a big Light Cruiser main battery. Her design was good enough to form the basis of the development of future USN CLs AND CAs (Wichita being the link vessel).
For the Escort category, my heart says the Black Swan Class Sloop. They packed a huge AA punch and later, in the form of the Improved Black Swan became extraordinary Sub Killers too. However, the best design was the US DE family. The basic hull design was perfectly suited for adaption with different machinery, armament and bridge design over the range, all mass produced and cheap, to provide the numbers needed to win the ASW war across the Oceans.
For CVL, it has to be the British Light Fleet. Although a little too slow, the economy this gave, as well as the larger complements allowed by the lack of an armoured flight deck, meant that this utility design was able to serve for many years, through boom and bust.
Art by the amazing Dixie