I'm an Australian atheist.. Hi :-) In my 20s I read and loved a lot of religious teachers. From Hindu gurus I loved Vivekananda and Ramana Maharshi (
The Gospel of RM) most of all. I read Maharshi again a few years ago and still 90%+ of it seemed right, because he says what he knows personally, not what he read or was taught. If you're more theoretically/philosophically inclined, try Nisargadatta Maharaj (
I Am That).
As a westerner, I also got a lot from the (white) US gurus Ram Dass (many, e.g. Be Here Now, Grist for the Mill, audio recordings of his retreats) and Gangaji (any of her books or videos). They couldn't be more different. I met an Indian woman here whose favourite guru is Ram Dass, so it seems Indians like him too.