I always like random acts of kindness. One CM saw I was by myself and let me sit in the premium viewing area for the fireworks at the train station - I was at the back, and she made sure first that there was extra room. I thought that was really nice.
When I used to get the kids the glow necklaces, I always got a couple of extras and had them give them to someone who looked like they could use one. We gave away a spinning light once. When we sit and wait for parades, I tend to put younger children in front of me (w/their parents' permission, of course) so they're up & close. We had two extra tix to Fantasmic Premium Seating, so I found a parent w/two children, who happened to be there their last night from Canada, and gave them the tickets. There were two parents, so the mom told the dad to take the kids. After the show, the dad went to get the mom to watch the fireworks with them, and I told the kids they should thank their mom for watching the show all by herself so they could watch it while enjoying desserts. The CMs let her have dessert afterwards, too - that was nice.
My kids & I were in front row watching the Snow White show from up top, and there were these two little girls crying because there were too many people and they couldn't see the show. Again, this family was from out of town, and it was their last night. I offered to let the girls sit at our table with us, and so they did - we got them light necklaces and they loved the show. Their parents came and grabbed them right after it was over (understandable cuz it was so crowded), and I don't think they ever said thank you - but those girls' faces were lit up - so happy, and that's what was important to me... There've been others, but then people do nice things for me.
Like the time that Tink33 called me up and asked if I wanted to join her at an "Event" that included breakfast at Club 33, then listen to talks from 2 of the original Disneyland Imagineers, and the daughter of one. That is something I'll never forget.