Try to list the name and Web site for the tracker, what features it has, what it does well, and then maybe a bit about what it doesn't do or have.
USDA's Choose My Plate Super TrackerEdit
You can create "combos" of food that you eat regularly for easier entry; can tag favorite foods for quicker access. The foods are a bit limited, and the search engine is not the best. But it calculates nutritional information for food groups and over 30 nutrients. It will help you see trends in your eating and how you are doing against nutritional standards.
It does not include any "social" mechanisms for chatting, blogging or user message boards.
It also includes exercise tracking. And it estimates how many calories you've burned.
You can enter goals and get good feedback about how you are doing in comparison to those goals. The goals are not just calories and exercise. You can, for instance, pick a vitamin that you'd like to track.
Site: http://www.myfitnesspal.com/ There are also applications you can add to a smart phone that let you easily track throughout the day.
Based on your goals and current information (weight, activity level, etc.), MyFitnessPal will make recommendations about caloric intake and exercise. Or you can override the goals with your own.
MyFitnessPal (or MFP as many users call it) has an extensive list of foods, both generic and brand specific, and it allows you to add foods. The database of foods has over 1 million entries (although some are duplicates).
It has an easy to use food diary. MFP keeps a list of recently eaten foods by meal. (You can select one and then change which meal to record it for today, but it took me a little while to figure out how to do that.)
The nutritional information and nutrients that you can track are more limited than some other sites (like the USDA Super Tracker).
MFP tracks exercise. And it adds to the recommended calories for the day based on the amount and type of exercise. (You can also add to the exercise database, but it is less extensive than the foods.)
MFP has multiple social mechanisms. You can "friend" other users. There are blogs, discussion postings and messaging. The discussion postings are generally very positive, encouraging and supportive. Although as the site warns, the advice is not being given by medical professionals (at least not in their professional capacity) so care should be taken in deciding which to follow.