1. Bilbo putting himself between Azog and Thorin. Sheer love! This whole scene really, from Azog and his warg completely trouncing Thorin, to Kili, Fili, and Dwalin coming to the rescue. But the best part, and my favorite part of the entire movie, is Bilbo standing between hunter and prey.
2. Crossing over into the Wild after leaving Rivendell. Again with the gorgeous scenery and awesome music. And I want to go hike these places so badly!
3. Bilbo wandering around Rivendell. No dialogue, just Bilbo taking it all in. His expression says it all.
As for a favorite line in this one. A toss up between Bilbo's "I have some skill at conkers, if you must know, but I fail to see why that's relevant" and Gollum/Bilbo's "If Baggins loses, we eats it whole" "Fair enough" exchange.