Best Actor of the modern era?

Really difficult to say. Actors suit different films so if you want popcorn action I think Tom Cruise or Bruce Willis do a good job but if you want something serious then Daniel Day Lewis, or Sean Penn are very believable. I would always give something a try if Tom Hanks was in it, or Julianne Moore. Kate Winslet has done some exceptional work, I really vibe with her characters and believe her. She has a lovely face. Tilda Swinton is cool. If I had to pick one I would say Jeff Bridges but only because I want him to leave his wife and run off with me. But he has done some reasonably good work too. The dude and True Grit, for example. Juliette Binoche is another I like to watch. Loads more.
In summary I cannot choose!

Mia Khalifa

Gene Hackman

Robert Duvall