My first NCL cruise was the Gem, in an owners suite and had the best butler and concierge. Next up was the Epic in the Haven, then Encore, Escape and Bliss. I like the bigger ships, more going on and different venues.
For me it would depend on itinerary, price etc. I was looking at an itinerary on the pearl and Prima/Viva. Same itinerary a little more the newer ships of course, I’d try the newer ships.
id say it depends what you value in a cruise and do some research, look up you tube reviews etc and make the informed choice.
Good luck