Cheers,
Funnily enough, my favourite gurus aren't really personal development people... not in the classic sense.
I do like people like Richard Bandler [who I'm going to go and study with in London later this year] and Milton Erickson, Virginia Satire, Jung, Freud etc...
But I'm mostly influenced by brilliant deep thinkers...
People like Peter Boghossian, Daniel Denette, Socrates, Gabor Mate, Jordan Peterson, Slavoj Zizek, Sam Harris etc etc to name a few.
I find a lot of self-dev to be really re-hashed and regurgitated circle-jerking ideas that in practice don't really work.
I was once very spiritual and somewhat romanticist, now a days I'm very much about science and what is pragmatic [i.e what works].
I really dig the work Ed Deci has done on his Theory of Self Motivation
And I'm a massive fan of the writing of Mark Manson
I love the 'You Are Not So Smart' Podcast by David McRaney
My tastes are pretty eclectic but often my inspiration and insight is from sources outside the personal development realm.