There isn't a "best".
Nicaraguan cigars may suit certain consumers more than Cubans, and Cubans may suit certain consumers more than Cubans. Some may prefer cigars from many different types of countries.
Cubans were undoubtedly the best back in the day, but cigar quality all around the world has improved immensely. Nicaraguan cigars are just as great as cubans now. Same with cigars made in Honduras too.
However, cuban cigars are so iconic. Have so much history and so many famous brands. With the likes of W. Churchill smoking Romeo Y Julietas and JFK smoking H. Uppmans... cuban cigars will always be branded as the best, and that will probably never change. So many massively famous people smoked cubans, it's hard to rub off that image.
I smoke cubans, because I can buy them in the UK. It's hard to get cheap Nicaraguan cigars here though, so I stick the cubans.
Nicaragua, most notably Estelí and Jalapa have an outstanding production of tobacco, and the Padron 1964 has consistently been one of the greatest cigars made. However, Cuban tobacco grown in the Vuelta Arriba and Vuelta Abajo regions are far more superior in terms of tobacco quality.
There is more to a good cigar than just tobacco quality. The roll, the factory, the conditions for storage, the age of the plant, these are all factors to making a good cigar. I'm sure most would say that it's a matter of taste, but I disagree. Cuisine can be judged on quality of the food and preparation. Hands down, Cuban cigars have something that no other country can produce.
Most of the naysayers are in the US where you can't buy Cuban products. The market is entirely from other areas. To be honest, once you go Cuban I think it would be quite impossible to change to anything else.
Cigars can be compared to Wine - Different palates taste things Differently. Listen to all that is said or printed - give it some thought - find your style - and then enjoy the stick that you find fits YOU the best.
There are do many good cigars in Central America . Apart from Nicaragua you also have the Honduran ones !
Or one of the best???