I've had a few great interactions with characters as an adult. When meeting Aladdin, I commented on his fez being cool, and we had a several minute conversation about Doctor Who. Of course, so as to not break character, Genie brought him some Doctor Who things from another time.
I have an autograph book with pictures of each character that I drew, so that always brings about a conversation when they ask if I really drew that, then they flip through the book to see the others and comment on the ones of their friends. Sometimes, they show another character that is near them, or just their handler or photopass person. Minnie kissed the picture of Mickey, then Mickey kissed the picture of minnie. This was at different times, so it's not like they saw the other do it first. This also brought a funny conversation when one character wasn't drawn yet, so I had them sign a blank card.
When meeting Belle, my husband was kind of standing to the side (he's not as excited to meet characters, but is willing to wait with me), and Belle said "I see you've brought your own beast!". I thought that was funny, especially since he's got bushy hair and bit of a beard.
Last year, I had gone to Star Wars weekends with a friend, while my husband was on a business trip in Orlando, so he came to spend a day and half with us. Since we are big Star Wars nerds, he had to wear around his Yoda backpack. While we were waiting in line to meet with Aurora, my husband went forward without us, and used his Yoda backpack as a puppet. The entire time, he only spoke to her in Yoda's voice, and she was phenomenal. She didn't break character, and had a full conversation with Master Yoda, in which she spoke directly to the puppet. Personally, I probably would have been creeped out by a tall, bearded man, apparently travelling alone, talking through a yoda puppet.