i would say ramanad sagar is best director o bollywood.

his film ghunghat in60 was a big hit. and it also show his talent of directing.

zindagi64,arzoo 65,geet70 are his best movies of all time.all these films lead role played by rajendra kumar.great kumar.

ankhein is his most successful film. dharmendra is hero of the film.ramanand sagar won filmffare award for that film.

main thing is the music of his films.all of his films are great musicalls .

of all the directors in bollywood u find the freaking Ramand Sagar as the best director, just to throw some light beyong Ramanand Sagar and Rajendra Kumar , there are legendry adirectors in the list, please feel free to pick up any and they can go into the list of one of the Best directors

Guru Dutt

Shyam Benegal

Satyajit Ray

mani Ratnam

Sanjay Leela Bhansali

Sai Prajpai (I hope u know who she is)

Hrishikesh Mukherjee

Vidhu Vinod Chopra

Ramesh Sippy

mistake of spellings .

the film neme of sparsh in above reply.

now there are many directors who are the best  right now i could remember on these names 

bimal roy

hrishikesh mukherji

basu chatterjee

manmohan desai

prakash mehra

sanjay leela bhansali

Yash chopra

Bimal roy

Raj kapoor

Bimal Roy

Shakti Samanta

Raj Kapoor

Mahesh Bhatt

Vikram Bhatt

Rituparno Ghosh

E.Niwas

Yash Chopra and Aditya Chopra

Amir Khan

K.Murli Mohan Rao ( who directed Kya Yehi Pyar Hain )

BEST DIRECTOR SHOULD

RAKESH ROSHAN

AND

YASH CHOPRA

Shyam Benegal,Rakesh Mehra,Raj Kumar Hirani,Sooraj Barjatia

What about Ashutosh Gowariker ? His Lagaan has been included among the top films in the Oscar and his latest JODHA AKBAR's sets are preserved as tourist attraction.