I am partial to LuckyLovers.net since I found my wife there after searching there for about one year. There are members there who have been around for 10+ years and new members daily. This site does not have the bells and whistles of others but it's much more personal, no tricks and customer service cares.
Pretty much any travel related business has reviews on Travel Advisor. And since there are so many reviews per business, it's the go to place to find reviews and suggestions. Also, if a business closes, TA will let you know. TA also gives you tips on itineraries and such which makes travel planning less daunting.