Of those 3 I was only somewhat happy with Anathem. I couldn't finish REAMDE and Seveneves convinced me that I may not read another one of his books again, unless it debuts to unanimous critical acclaim or something similar. I thought the ending of Cryptonomicon was pretty weak but the rest of the novel leading up to it was so fantastic that I didn't care. Honestly I found the Baroque Cycle to have the best ending of any of his works, and I would describe it as the one time I was happy with both the journey and the destination of a Stephenson novel.