Hi,
Super achievers??
Like Jeanne I too am older than dirt,haha.

The books which I consider the most influential are many more than three, but here goes.

YOU FOREVER by Lobsang Rampa
This was published in the 1960s as part of a whole series of books starting with the THIRD EYE. These books are what made me seriously realize that I am not my body and started me on the path.

A COURSE IN MIRACLES
A daily lesson for every day, lasting a whole year which can move you on and help you to make great strides spiritually.If you follow the lessons and persist. The writing can be a bit pedantic, but sometimes, there it is ! that phrase which lifts you and you instantly recognise as truth, and this book contains many.

THE POWER OF NOW - Eckhart Tolle
Charts Eckharts awakening and journey to becoming a writer and spiritual teacher. It is an amazing book with so many insights.

Along with these I'd have to add the Bhaghavad Gita. Indias ancient spiritual tradition cloaked in the stories of Arjuna and his journey.

As a reading list for a spiritual seeker I'd definitely include all the above as they have helped me enormously.
I think as you only ask for Life Changing books you are going to end up with a massive list as everyone is seeking and their priorities differ.
Enjoy
Love and light
Faune