Tripadvisor lists tour options for many of the available attractions. Many of the individual tours have lots of recent reviews so you can get a better idea of what the experience will be like.
There is a lot of incentive for companies to post fake reviews in order to increase their ranking/visibility. Tripadvisor does very little to catch the false reviews, so it's hard to know what's authentic and what isn't.
Rather than give you a long list of all possible attractions, wikitravel lists only the most popular/must see spots. This saves you time when picking out quality attractions.
There are very few pictures of the destination, with none (in most cases) of specific attractions. If you want to get an idea of what the attraction looks like, you'll need to find images on google or other sites.
Wikitravel, true to the format of Wikipedia, doesn't have ads, and the content isn't worded in a way that makes readers feel like they're being pitched to go somewhere by a travel agency.
You can only explore destinations by continent. There are some interest categories that you can also check out, but they don't have a focus on specific destinations.
In 2014, Foursquare split into two apps, moving the social components to an app called "Swarm".
With the removal of the social interaction from Foursquare, the number of active users started to diminish. This resulted in fewer new reviews.
Along with having a photo gallery, each attraction has a small description, plenty of reviews and a map. The "Tribe" feature tells you what type of travelers enjoy that attraction the most (Outdoor Enthusiasts, Local Culture, Adventure Travelers etc.).
Each attraction has a photo gallery that any reviewer can add to. Many of the galleries are quite large with great pictures of the attraction, so you can get a good feel for whether or not it's something you're interested in.
Rather than provide a long list of attractions, TripExperts only show the best attractions in a specific area based on expert reviews. This makes it much faster to find quality attractions, rather than searching through hundreds of less interesting options.
You can download offline data per city or parts of cities if you live in an especially large city, but not for states or countries. Points of Interests are generally more relevant & current than the typical stand alone GPS unit.
Couchsurfing does not provide a list of available attractions in various locations. The only way to discover things to do on your trip is by chatting in the groups or by sending messages.
Group members are made up of both locals and travelers. Participating in the groups gives you a chance to ask locals questions and get insider information about the best spots.
Fodor's Travels makes it easy for you to scan a destination and see if it's a good place for you. They cover top attractions, when to go, travel advice (such as health and what to wear), and have a photo gallery.