From first hand experience, I'd have to say that after spending 8 days in Northern India, the only people who DIDN'T want to rip me off, or greet me with a view to touting or selling me overpriced services or guilting me into tipping them or guilting me for not tipping enough were the Sikhs. Our first hotel was run by a Sikh because he gave us a fair price for a nice clean plain couple of rooms.

If I go back to India, I think I'd like to spend more time in Punjab. It's the only place where I felt welcomed.