Magician
Its something of a classic, I’m actually reading it again… by again I mean for the fifth time. What? Don’t judge me!
I’ve worked my way backwards through Feist in certain respects, it was mainly Talon of the Silverhawk that drew me into the series and even then as the result of hooking another friend. The Conclave of Shadows trilogy and its following work are easily my personal favourites after the core novels surrounding Magician.

Worthy of note in this entry is Gifts by Ursula Le Guin, which is followed by Voices and Powers (Which I am assured are also promising reading). I was moved to tears at one section of Gifts and found it to be deceptively twisting in its direction, something that might not sound like a positive but which is part of its overall genius. I like literature that does not dish up a perfectly happy ending.

If your interest is prickled then head for a search engine near you, I’ll get round to adding links at some point however

Updated:
Gifts (Its a bargain at £4… I actually got mine in PERFECT condition from a second hand bookshop for thirty pence… I was thrilled!)
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Magician (Riftwar Saga) (You probably own this one already)