For me, it was The White Dragon first. I think I was around 14 at the time. I have since read all of the Pern books written by her (although I've avoided the ones that have her son's name on them).
That was my first also. From them on, I was searching for all of them. Her story of how they got to Pern in the first place speaks to us today, doesn't it? I wonder if we will ever send colonies out successfully. Anyway, I have already chosen for my next life to be on Pern.