NEW YORK - The 10 most popular New York City hotels on TripAdvisor have attracted about 12,500 reviews - and more than 10,000 of those belong to a group of four boutique hotels.As I write this, the Casablanca Hotel is one of four Library Hotel Collection properties in Manhattan which for some time now have all ranked in TripAdvisor's top 10 of New York City's 454 rated hotels - no small feat - with more than 2,000 reviews each. The Casablanca is number two (with more than 3,500 reviews), Library Hotel number four, Hotel Giraffe number five and Elysee Hotel number seven.Why have these hotels, which have all won several accommodation and service awards, attracted so much positive attention from their guests? New York City is big, bold, brash, busy - a city on steroids, especially around Times Square and everywhere at rush hour. People are reasonably friendly, but on the frantic side: they are busy busy busy so you don't normally expect too much TLC.That makes the approach at the Casablanca Hotel, just a few steps from the heart of Times Square, both unusual and welcome. An offer of free bottled water during the heat of summer is only one of the "we take care of our guests" features."Escape to Serenity," is the heading on a note on the bedside table in every room. "Missing the comforts of home? These items are available with our compliments" - and the two dozen items range from earplugs and comb to mini-refrigerator and SleepPhones ("pajamas for your ears that block noise and play soothing music"), says sales and reservations director Monika Argueta.Then there is the deluxe continental breakfast, including 12 cereal varieties, which can easily serve as brunch. And the deluxe winecheese happy hour every evening from 5 to 8 p.m., with pianist James (not Sam) every Friday. There's also complimentary coffee, tea, cookies and fresh fruit 24/7. All four hotels offer the two dozen complimentary amenities, continental++ breakfast, evening happy hour and 24/7 coffee-teacookies-fruit.Each hotel has a theme. At the Library Hotel, for example, with its 6,000 books, each of the 10 guestroom floors is dedicated to one of the 10 major categories of the Dewey Decimal System. And each of the 60 rooms has its own topic (and books) - from advertising and erotic literature (a popular choice, according to Tim Gerhold, front office manager) to paranormal and zoology.All the LHC hotels offer special rates and packages. For example, the Library Hotel takes erotic literature (Dewey Decimal 800.001) to the next level with an Erotica Package, to "ignite your passion." It includes a bottle of Veuve Clicquot Champagne, one dozen red roses, Belgian chocolates, two plush Library Hotel signature bathrobes and "the Kama Sutra romance kit packed with massage oil, body dust, serenity bubble bath, a feather tickler and playful wild cards plus, of course, your very own copy of the Kama Sutra, all yours to take home."Quite a collection, although perhaps not quite what the words "library" or "book review" might suggest.