Hi Sid - no big deal here... As we always do for other tickets, just go to expedia.co.in or makemytrip.com. Try to book on a weekday like Tuesday/Wednesday. It will be generally cheapest in the middle of the week. What I do is - see the cheapest airfare and go to the actual airline website and book from there...
For eg., last time I went, I checked in makemytrip.com and I saw the BA ticket was cheapest. So, i went to BA website and saw for same day. It was 500/- lesser than makemytrip, so booked from airline website directly....
My experience to Toronto - BA service was good, especially liquors and frequency of food. While returning, I booked Jet Airways. In Jet, the flight was good and food taste was very good, but quantity was less and frequency was also less. Very kanjoos kind....
For other destinations, other carriers may be there... check it out...