After sailing on every multi-ship class last year, it has to be the Dawn or the Jewel class, just because we had better service, shorter lines, and the crew seemed to be happier.
Sun class is just too old, although the Alaska cruise was fun, the ship creaks more than I do.
Breakaway and Breakaway+ ships seemed to be always overbooked, with long lines and too many entitled PAX and pissed-off crew.
Sadly the Prima class, wished for more but with the ship design geared for warmer climates, once you have cold / rainy weather, everything seems jammed up inside.