So, I downloaded a handful of apps and then stuck with the first two. I never did use sparkpeople.
Lose It! is about the best app out there, but the food database is not so great.
thedailyplate/livestrong has a better food database, and is more comprehensive, as well as synching with the website, but it just doesn't feel quite as convenient to me so I use lose it! If I really wanted to sync though, I'd use thedailyplate. Also, thedailyplate has a massively better food database, so I often search it when lose it! comes up blank.