I use FitDay, and I don't want to switch because of all the stuff I have stored on file with them.
I find they FREQUENTLY don't have things that I eat and I will end up looking something up at one of the other two sites and entering the information by hand into FitDay. There is definitely not as much of the brand-name stuff on FitDay.
But they have seemingly unlimited "Puerto Rican"-style things
... Can't figure that out. I don't have anything against Puerto Rican food, it's delicious, but I don't know why there is so much of that when I've never seen "Peruvian"-style or "Mexican"-style or the like. Also it irks me that they don't have things like agave nectar or fat-free refried beans but they do have human breast milk and "chocolate gravy"
Also - FitDay does not track sugars or - oddly - folic acid in the nutrients section so if either of these is important to you, use a different site. And one more thing - alcohol goes in its own category instead of being counted with carbs.
I do like all the charts and reports that FitDay has (don't know if the others have the same). BUT if I had it all to do over again, I would enter in a few unusual things that I eat regularly to see how each site fares - and/or use each site for about a week (so you don't lose too much if you bail) before committing.