Hii, 

These are the highest paid doctors :

• Plastic surgery, 
• Nuerology
• Orthopedics,
• Cardiology,
• Gastroenterology
• Radiology
• Oncology,
• Rheumatology

These department in medical field keeps on flourishing and have very bright future ahead. And are also toughest to get these departments as a career option because the competition is very high among the growing medical aspirants.

Hope this helped!

Good luck.