Here are the world’s very best cruise lines for 2018. Take the recommendations of Conde Nast Traveler readers, who cast their votes for the best cruise lines of 2018. Winners are grouped by size, mega, large, medium and small ships, so that cruises rank on level playing fields.

In the mega ship category (defined as ships that carry more than 4,000 passengers), Royal Caribbean International was deemed the No. 1 cruise brand for its portfolio of titan ships including the Symphony of the Seas, Harmony of the Seas, Allure of the Seas, and Oasis of the Seas. With amenities that include everything from onboard ziplines to robot bartenders and en-suite tube slides for kids, the ships in the Royal Caribbean fleet are state-of-the-art.

Here are the best cruise lines of 2018, as voted by readers of CN Traveler:

Mega Ships (more than 4,000 passengers)

Royal Caribbean International 87.74
Norwegian Cruise Line 82.60

Large Ships (2,500 to 4,000 passengers)

Disney Cruise Line 92.95
Princess Cruises 88.32
Cunard 88.19
Royal Caribbean International 87.02
Holland America Line 85.69
Celebrity Cruises 85.13

Medium Ships (500 to 2,500 passengers)

Crystal Cruises 96.96
Viking Ocean Cruises 95.55
Seabourn Cruise Lines 91.73
Regent Seven Seas Cruises 90.99
Cunard 90.40
Oceania Cruises 89.25
Disney Cruise Line 88.72
Silversea Cruises 87.40
Princess Cruises 86.65
Azamara Club Cruises 84.09
Royal Caribbean International 83.75
Holland America Line 83.58
Star Cruises 81.72
Celebrity Cruise 80.31

Small Ships (fewer than 500 passengers)

Seabourn Cruise Line 96.40
Crystal Cruises 95.16
Windstar Cruises 92.99
Regent Seven Seas Cruises 92.48
Paul Gauguin Cruises 92.39
SeaDream Yacht Club 92.01
Lindblad Expeditions – National Geographic 91.88
Compagnie du Ponant 91.83
Celebrity Cruises 91.29
Silversea Cruises 91.22
American Cruise Line 90.93
Quasar Expeditions 90.05
Quark Expeditions 86.06
Sea Cloud Cruises 85.48
Star Clippers 82.63
Hurtigruten 81.92

River Ships

Viking River Cruises 98.99
Crystal River Cruises 98.80
Uniworld Boutique River Cruises 98.55
AmaWaterways 97.91
Grand Circle Cruise Line 97.49
Avalon Waterways 95.49
Tauck 94.68
Emerald Waterways 93.89
Scenic Luxury Cruises & Tours 93.25
Travcotels 90.83
French Country Waterways 88.93
Vantage 87.85

Find the full results on CN Traveler.