I fly to India once a year in Business using United miles. UAL and Star are the best options as others here have mentioned.

Ideally, I prefer flying one of United's partners because of their superior product. Last year, I was able to find availability on Jet for the LHR-BOM sector. This winter, I will be on Asiana trans-pacific and Singapore from ICN onwards. I booked these tickets over the phone since not all partners are available online. The $25 phone booking fee is well worth it.