I would recommend Roger McBride Allens Caliban-Saga/Trilogy
I enjoyed reading it, and I think it even fits nicely into the whole Robots-Storyline. (In so far as that it doesn't really touch it, but doesn't read as if it's in a parallel universe either.)
OTOH, the "second Foundation Trilogy" I don't recommend. I only read the first two books but that was cruel enough. No doubt both authors are good at what they do, but neither tried to imitate Asimovs style - which is fine by itself, but if they contradict the original story by introducing things that can't have existed, it starts to get annoying.
(Note: I read the german translations of those books.)