Gordon, over at RuneSoup.com, regularly makes posts about what the various blogging/writing magicians have taught him. I am going to briefly steal his idea form a longer term perspective.
"Fred" - introduced me to the idea that magick existed.
Mary Greer -- Doing the Work is looking within.
Donald Michael Kraig -- basic ideas, theories and rituals. I'd argue with some of it now but then it helped.
My former group -- (through negative experience) We all have huge blind spots. Treat them with compassion.
My Mentor -- nothing I could write here would do it justice.
Sam Webster -- semi-privately supplied me with a great compliment when I really needed to hear it. He also conveyed various facts regarding GD theory during the time my mentor was instilling personal alchemical knowledge. Sam and I only speak briefly once a year at Pantheacon but I still recognize him as very important to my early work. Given that one of my personal beliefs is that every thing we do is deeply influenced by the forces present at their inception, I am grateful for his early influence.
Lon DuQuette -- his books and conversations helped me to form my own qabala.
My Gal -- find things to enjoy! (that doesn't sound magickal to many, but it is)
John Michael Greer -- all scholars are not arm chair magicians. I really respect his scholarly approach to things and the contributions he has made toward preserving the traditions. My GD is not your GD.
Rufus Opus (RO) -- Spirits are real
Jason Miller -- shifted my perspective on spirits; taught me to make offerings and gave me a direction to further my GD work by going in a completely different direction. That and his work resulted in me finding the Helpful Deity, which may be the most personally satisfying magick I've ever done.
The nameless initiatory officers. I've been experienced all the outer order initiations in GD work. That means a lot of people have taken time out of their lives to perform a service for me. Some of these people are well known. Others you've never heard of. The experiences I have had as a result of those initiations are invaluable. To them I have always said, "When I am ready, I will do for others what you have just done for me." I suppose that is true for all of the above.
When I look at that list, I am amazed at the magickal talent it represents. The Universe has been good to me.