I'm going to recommend someone who hasn't acted much but is on radio and television all the time. When I first met her I couldn't believe she'd read Atlas over 30 times. After reading it myself and listening to how she intuitively understands Ayn Rand's message of objectivism, I think she is the real life Dagny Taggart. Heather Wagenhals from HTTP://UnlockYourWealthRadio.com is an amazing candidate for the role. I may be biased because I share my speaking platform with her, but she is the right age, has the right look, and of course she's Dagny all the way.