Finally, I sent $35K from Chase wire transfer. It took 3 business days to get it deposited in Nabil Bank in Nepal. Chase deducted $40 for $25K (Max amount) and another $40 for $10K. Total I paid $80 for $35K. Still, the deposited amount was better than any other transfer agencies. But, NABIL did not deposit based on the NRB rate, rather it deposited based on their own rate which was around 15-30 paisa less than NRB buying rate.
So, based on my experience, below is what I think would be good:
"Utako utai yetako yetai is the best" if its small amount as no legal complication for small amount.
Wire transfer is most reliable,legal way
Transfer via Prabhu money
Thamel is next
and so on