The Final Reveal on whether or not Arroway really did meet the aliens:
"I was especially interested in the section on Arroway's video unit. The one that recorded the static... The fact it recorded static isn't what interests me... What interests me is that it recorded approximately eighteen hours of it."
The childlike awe on Elenore Arroway's face as she perceives the Milky Way galaxy from the outside, looking in at a newly forming planetary system, and weepingly repeats to herself, "I had no idea...I had no idea..."
No words, no words...they should have sent a poet...
This is somewhat subverted by the fact that if you've been paying attention to the set dressing, every scene she's shown after entering the second wormhole comes from her own memories. They are all from posters she's had up in her quarters or workplaces. Amazing visuals, and amazing acting, though.
News Reporters: Reverend Joss! Reverend Joss, what do you believe? What do you believe?
Palmer Joss: [pause] As a person of faith I'm bound by a different covenant than Doctor Arroway. But our goal is one and the same: the pursuit of Truth. I for one believe her.
A special mention goes to the film's introduction. See it here.