One of the reasons why I think I have the best-paying "job" in the world is "the look."
There is a look that you get from animals (if you're very lucky) of absolute trust. It's this look in their eyes that says "I know you will never hurt me." I get it from Cipher (The World's Most Amazing Cat, Screw You if You Don't Agree tm) right before she falls asleep with her nose touching mine. It says to me that she's willing to completely unguarded around me because she knows that she's safe.
I get it from certain cats at the shelter when they curl into my lap and settle in for a good snuggle. These cats barely know me and yet they are trusting enough to believe that they are in no danger from me. The big high is when you eventually get it from a cat that you've had troubles with. The shy cats or the aggressive ones. The ones that for the first 10 visits hid under the chair or hissed whenever you approached. But with the love and patience of the volunteers, they slowly begin to relax and get used to the attention. They don't hide in the corner. They don't try to use your hand as a chew toy. They come closer, give out with a rusty purr, and rub their cheeks against your hand.
And then, if you're very, very lucky, you one day get "the look." And that makes all the scratches and all the hard work worth it.
I love "the look."