I want one that's fun to read, and one that is not horrible anti-communist propaganda. I tried to find a biography myself but it turned up a bunch of weird reactionary books as well as some that just look boring. Also idk if this is the right community for this question? But I hope so...
Michael Heinrich is undertaking this project right now. The first book is "Karl Marx and the Birth of Modern Society." It's on my shelf, but I haven't had the chance to read it, yet. Heinrich is primarily known for "value form theory." He's somewhat controversial among theorists, but is a committed student of Marx.