Let's not forget that the command crew of a starship are likely to be bolder, more selfless, yes, more heroic than the average schlub. And these characters gave us people to emulate. I've stuck my neck out more than a few times for others; Star Trek and Superman may have had something to do with that.
Just to mess things up, I'll also toss in Kirk's line in TFF:
"I'm afraid of nothing."
Weakest line of the movie. I'm amazed at how Shatner got so much of the other characters right - I never expected that - but his Kirk came off as petty. I prefer to look at the line in context, as if to say he fears nothing within his own psyche.