Which medical specialty would you say has the most variety, lacks mundane repetitive stuff and is intellectually stimulating?
You fail to understand the bigger premise that the more mundane conditions like diarrhea LRTI, typhoid, malaria, Hypertension and diabetes in Medicine are the diseases that bring maximum revenue to the doctors from a economical stand point. You can always find some interesting cases amongst them but most of your cases in any field with be mundane. If you want to deal exclusively with Dr House cases you need to become a professor in a hospital with the RMOs and PGTs dealing with the mundane stuff and you dealing only with the extraordinary ones
I would say medicine and pathology, provided they are done from a good institute that offers a great variety of cases and exposure.