If “best” means most theoretically capable, regardless of actual battle results, then the latest and greatest design is almost always the winner. Since they aren’t being built anymore (Ranchoth’s silly thread How might you build an "updated" Iowa class battleship, today? - Factual Questions - Straight Dope Message Board notwithstanding) the last design is probable the best. That’s Iowa as so many have already said.
My point is that it’s best simply by being newest, not by being inherently bestest. Had history been different the Japanese or Russians or Germans or Brits may well have built something much better in the 1950s. Which would have in turn been leapfrogged in the 1960s.
The Iowa class is simply when the music stopped for battleships. In a sense, that’s a win by luck, not skill.
I agree with casdave that these specifications dick-waving contests are the usual armchair fanboy way to talk about weapon systems (or cars, guns, supermodels, etc.) but it’s grossly misleading and amateurish as military analysis.
IMO the “best” battleship is the one that did the most good in its time to advance its country’s agenda at the least cost in blood and treasure.
I am not enough of a naval historian to answer that question. But I think that is not merely the proper question to ask, but really the only interesting question to ask. Otherwise, for almost any technological topic the answer to “which is best?” can be answered “Whichever is newest.”
Here’s an anecdote to support my point. Last weekend the last flying B-17 & B-24 happened to be at my nearby airport. Wife and I took the tour, crawling through the fuselages of both. I grew up going to warbird airshows and my wife was USAF too. We’d both seen plenty of WWII warbirds & later warplanes over the years. Still the tour and conversation was sobering to say the least.
I compared the B-17, heavy bomber *extraordinaire *of its era, to the F-16, a small lightweight fighter by modern standards. The F-16 can carry 4x the bombs, 3x as far, 4x as fast, deliver them with 100x the (unguided) accuracy, and expose 1/10th the number of men to danger.
Is the F-16 a “better” bomber than the B-17? Or just a newer one?