I did seven episodes of an NBC sitcom called "The Jake Effect" (with Jason Bateman) before it was cancelled. So I was looking for a new show, and was meeting with other networks until NBC said:
NBC: "Hey, stop meeting with other networks. This is the time to be getting you something at NBC."
Me: "You guys haven’t been sending me anything."
NBC: "We thought you only wanted comedies."
Me: "No, I'll do anything. Send me something good."
So "Heroes" shows up at my house. It came with pictures and sketches and drawings and illustrations, maps and WARNINGS. Every page was numbered and marked "Top Secret," so it was clear, right away, that [creator] Tim Kring was a freaking genius. I immediately call NBC:
Me: "Okay, I am ready to play Peter Petrelli. I'll do it!"
NBC: "Well, Tim Kring doesn't know who the hell you are."
(What, he didn't watch "Felicity"?!)
I agree to audition.
And I thought I did a good job. I thought I nailed it. I left and as I am driving David Semel [the director] calls:

David: "Hey, I got some good news and I have some bad news. The good news is they really loved you… Well, on second thought let me give you the bad news first. The bad news is that you are so wrong for the role of Peter Petrelli, I can’t even begin to tell you."
Me: [silence]
David: "And there is a guy they love and his name is Milo Ventimiglia."
Me: "What? They're hiring a pasta over me?"
David: "There is this other role of the mind-reading cop named Matt Parkman. If you like it, they'll offer it to you."
What? That’s like a dream. I read it, I loved the role more than any of the other roles in the whole show. So, again, I call:
Me: "I'll do it!"
The rest is history.