OK. After some serious research, I found out the best way. Open a CITI NRE account in your name, and then use Remit2India to transfer money from your US account to your CITI NRE account in India. On R2I's website it says you can only transfer upto 5K on ACH, but I called R2I's customer service and they said there is no limit even on ACH.

On large amounts (over $10K) you can get a better rate with CITI if you talk to the CITI NRI banker in any CITI NRI US branch. But Remit2India rates are even better.

Today's rate comparison for large amounts:
CITI NRI (using banker): 39.10 (no service charge)
Remit2India (using NRE-ACH no limit): 39.42 (Rs 99 service charge per transaction)

Hope this helps others