There are so many possible answers for this one. I mean that seriously. All three of the guys get so excited when they're getting good evidence at the location, it's always fun to watch. Sometimes just watching for their facial expressions is fun. Especially with Aaron. *grins* He makes some of the best faces.
Top reaction though has to be Nick at Linda Vista Hospital in Los Angeles when he saw the woman standing in front of him. I really think that everyone would have pretty much the same reaction that Nick did, and that's one thing I love about these guys, they don't hide their emotions while they're on location. I just can't imagine what it's like to look up and suddenly see someone standing in front of you. From across the room, yes, I do know that one, but not as close as Nick was to this spirit. I wish they'd been able to figure out who she is and what she needed.