I used to use FakeSpot to check Amazon products for fake reviews, and it's still a solid service that I recommend. However I like ReviewMeta. It looks like a more transparent system to me and I think they have been doing it longer, so I feel like I can trust them a bit more.
But the primary reason is because they have a Chrome browser extension. It makes it so much easier to check the corrected review score (which shows up on the extension button) or to generate a score for products not previously analyzed (just click the button).