I’ve had good experiences with MyHeritage and AncestryDNA. Both of these companies have a huge number of individuals in their databases. With patience and dedication, you can find lots and lots of historical and living relatives, and grow your family tree very nicely, using either company – although the databases skew heavily toward families of European descent.
On paper, OneGreatFamily should also be a good tool for discovering multiple generations of your family. But OneGreatFamily hasn’t found any of my relatives in its database. So I think it’s basically a scam.