Which Asimov Novel Should I Read?

Which novel by Isaac Asimov would be best for me to read for my English assignment. I think my teacher would prefer it to be a novel rather than several short stories compiled as one book such as I, Robot. Anyway, I’m pretty much looking for his most famous work. Something that captures Asimov’s writing style. Also, one that began one of the series as opposed to one in the middle of a series. Preferably average length as far as novels go.

Additionally, one requirement is that I can find 10 critical sources written about the book. So I wouldn’t think I’d have any trouble with one of his more popular works. Am I right?

So, collective, what’s book is best given the situation?