The Ming had good Emperors, actually, but the key with the Qing was that their three good Emperors ruled for *very* long in total, and so they could establish a good, solid foundation with which to build upon until Qianlong eventually became arrogant in his senility. Even the horrible Wanli's reign of around 40 years could be split into a good first half and a sick second half.
I'm not saying that the Ming are better than the Qing, they're just a normal dynasty with its fair share of good rulers, despots and wastrels. The Qing just happened to have those three (or at least, two of them, but Yongzheng's period was also critical) last for a really long time. Post-Qianlong I am also very sympathetic to Guangzu and his efforts, but the poor man never really had a chance. That was a man who could have bought more time for the Qing.