DittoI love Clarke but it's Asimov by miles for me. While characterization is not my top concern, I've never understood the common reaction about it. Susan Calvin, Baley and Olivaw, Giskard, Hari Seldon, Bayta and Arkady Darell, the Mule--these and others live strongly in my imagination. Other than Bowman, Poole, and HAL (mostly due to the movie), I can't name a single Clarke character. But both created great works of imagination, full of ideas and interest. Clarke has some smaller-scale but extremely vivid and compelling tales like A Fall of Moondust and cosmically grand, mystic (but somewhat nebulous) things like 2001. It's mainly that, in addition to great miscellaneous works and the fascinating sociology and logical permutations in the Robot novels and stories, Asimov's conception of the Empire and Foundation has blown my mind from childhood to now like few other things have.