Best Carriers in the world.

Are we talking in terms of gameplay or real world performance?

Probably Lexington class, both in and out of game.

A quote from a naval historian;;

   Ark Royal was probably the best, and in many ways was the pinnacle of the interwar designs. A good airgroup of 60+ (even without deckpark!). Fast, maneouvrable, with an extremely powerful anti-aircraft armament, and enough armour to continue operations after the sort of the damage that usually sunk or drydocked Japanese or American carriers. Her main problem was the poor quality aircraft available early in the war (which was largely an issue of the Fleet Air Arm only coming back to naval control in 1938.)

   She served magnificently until late 1941, and, with her long term partners – the heavily modernised battlecruiser Renown and the cruiser Sheffield and their destroyer escorts – she pioneered the techniques later thought of as ‘Fast Carrier Task forces’. Had she survived until the availability of Wildcat's, Hellcat's and Firefly's instead of Fulmar's; and Barracuda's and Avenger's instead of Swordfish and Albacore's: her value would have increased even more.

   She was unfortunately sunk by a single torpedo, due more to the new Captain’s panicked attempt to evacuate the crew quickly rather than see what damage control could achieve. (Admittedly the suprisingly quick capsizing of the Great War design Courageous was in his mind.)

    It would have been fascinationg to see what Ark Royal, with a deck park lifting her airgroup towards the 90-100 mark, could have achieved in the Indian Ocean or Pacific. She would certainly have been transferred to fight the Japanese in the Indian Ocean had she survived a few months longer, as she was more suitable there, leaving the heavily armoured Illustrious class in the more vulnerable Mediterranean fleets. For a design limited to 22,000 tons by treaty, she was an astonishing achievement. All the sadder that her loss to a single torpedo revealed design and handling flaws that should not have been fatal.

Akagi would probably be my second choice, maybe not the most practical but absolutely a beautiful ship.

Ark Royal was definitely the best British carrier in 41 but her airgroup could never compete in a carrier battle. She had the best armor yet ended up not being very survivable.

I'd argue the Yorktowns were better than the Lexingtons for the USN. Lex had a bad length to beam ratio for a carrier, too long to have a tight turning radius, hence the class constantly eating torpedoes, and too narrow to have the best hanger facilities. The Yorktowns proved to be massively survivable and able to operate after sustaining damage.

Shokaku was the best IJN design, although other IJN carriers are said to have had better trained air groups. This design and her air group together were the best until the Essexs rolled out.

I agree with Lcdr Swizzle. The nature of this thread implies that the discussion should focus solely on what people consider to be the MOST capable carrier in 1941, not the most efficient for its tonnage, the most beautiful, etc. Anyway, I personally think it is futile to try to rank units from best to worst, considering the fact that each one of these ships had its own strengths and weaknesses. That being said, the Shokaku class (just like the Yamato class), constructed free of Treaty limitations, was designed to have no equal among her foreign counterparts, and as I stated previously, a number of naval historians and experts consider the class to have only been surpassed by the Essex class of 1943. 

HMS Illustrious needed some love.