Who was the most lazy, incompetent, unprofessional, or creepy doctor you ever had?
I'll go with incompetent.
I had a pneumologist once when I was in university, who diagnosed me as having tuberculosis. The yearly radiology done by the university showed I had a mass in one lung and I ended up seeing an elderly specialist. I was treated with antibiotics for 2 years and then when nothing changed, it was then diagnosed as a benign cyst.
Only a few years later it turned out to be a tumor, luckily benign (a teratoma, a sort of stem cell cancer present at birth already).
After the TB was found to be a wrong diagnosis, I never saw him again. But it ultimately cost me a whole damn lung when years later I started coughing up blood and went to the hospital (yes while driving and spitting out the window). Two days later an operation and a lung less.
Ah yes, and a cherry on top: when they sent a rush tissue sample to the lab during the surgery to determine what sort of tumor it was, it was incorrectly diagnosed. The surgeons told my wife I wasn't going to leave the hospital.
A week later, a more leisurely and careful tissue diagnosis was performed and it turned out to be benign.