At last year's May MCM Expo, I was with my mate (he was Stan Smith from American Dad and I was Thor) as we were trying to find one of our other friends who'd disappeared somewhere. We were then chatting with this dude dressed as Spider-Man when suddenly, we heard the excited, high pitched cries of "Dad! Look! It's Thor and Spider-Man!"
We turned around and saw this guy and his two boys dressed as Mario and Luigi, who looked so over the moon to see their favorite characters and begged us for a picture. One of them even asked my friend if he was a SHIELD agent because of his suit.
Also on the same day, I saw this adorable little boy dressed as Captain America, who was there with his parents. His mum saw me and pointed at me saying to him "Look! Who's that?" I gave them a smile and waved and even though he seemed very shy, he grinned back at me. I felt a bit bad because I think he wanted to give me a hug, but the place was so crowded that we were all forced to keep moving along. But at least I made it a good day for some kids.