Mani, While Medical courses like MBBS, BDS, Ayush and Veterinary courses that are the conventional courses that every Biology student hopes to join, due to the lheavy competition and limited seats, students also go for other paramedical courses like Physiotherapy, Occupational Therapy, Rehabilitation Therapy, etc. Radiology and Lab technician courses are also good. Then there is Agricltural sciences, Bio technology, Micrbiology, Fisheries, Pharmacy that you can study. You cannot point one course and name it the best because Science is a Borad subject. Infact CBSE has released a list of courses available for Students post their 12th and you can check the list at their official page: http://cbse.nic.in/newsite/attach/Compendium%20of%20Courses%20after%20+2.pdf