Lots of great recommendations, thanks!! To whoever said Bill Bryson A Walk in the Woods, I'm currently re-reading (again) and dreaming of a long hike in the wilderness with BB for company.
I don't have one favourite, but here are a few that I would recommend:
Gloria Steinem - My Life on the Road. Not just a chronological autobiography, but peppered with cool stories and observations from an incredible life.
Francesca Martinez - What the Fuck is Normal. Another amazing woman, and so funny. She talks about getting into comedy and how her disability shaped her.
Victor Frenkl - Man's Search For Meaning. Short but really inspirational. I thought about this book for ages after reading it.
Bill Bryson - A Walk in the Woods, or Notes from a Small Island. Or any of his travel books really. I love his writing style and usually very funny.
Dr. Marie Cassidy - Beyond the Tape. If you're interested in Forensic Pathology this is a great one, she is the former Irish State Pathologist and talks about how she forged her career and different cases she had to deal with, pretty fascinating job.
Mark Bowden - Killing Pablo. The story of how they brought down Pablo Escobar. I read it a few years ago, was really good.