I doubt it's the greatest thing, as I will usually try to help people if they request or need it, but most recently:

I was riding the bus to the airport to take the train into town (I live in a pretty big, pretty hostile city, but not Detroit) As I was getting off the bus, the bus driver called me over (I take the bus often and we usually nod at each other in recognition) and asked me if I could help this man find the train station, because that is where I always asked to get off. I say sure, no problem, and he points to the man and I walk up to him and say "Hey, how ya doin, the train station is this way, follow me." He's an asian fellow, pretty old, I'd say he's probably in his late seventies, short guy with a briefcase, looks pretty well off. He looks worried and pulls out a piece of paper with a google map on it, but the writing is in Chinese (I'm pretty sure it was Chinese- I took a Japanese caligraphy class once and it didn't look like Japanese, and I love Korean food and it didn't look anything like characters on a Korean menu). He just points to the place and says "I going here, please. Thank you." Shit. this guy doesn't understand a word of English and his hotel is in the middle of a fucking metropolis. I buy a ticket from the machine, slowly, so he can see what I am doing, then try to help him buy a ticket. Machine is out of change and all he has is a $20. I buy the ticket for him, he tries to give me the $20 but I am not going to charge the guy $20 for a $2 ticket. He bows, I kinda bow, not really sure what to do. Whatever. I put the address into Google, and start to look for it. He sees this, and does the same with his iphone (which is in chinese characters, except for the hotel name and address), then holds up the screen to mine- so we're on the same page. Good. I can show him how to basically get there. It's pretty much downtown and he can use the navigation app to get him there from the stop, maybe 5 blocks away. I'll show him where to get off and continue up the line to my destination, a few miles north. As we get close to his stop, which is right by a big stadium, I realize that it is a late season home game for our NFL team- if we don't win we don't make the playoffs. The city is mobbed, the train fills with drunk assholes, everybody is shouting, the streets are choked. He starts to freak out and I gently grab his arm and say its okay. He repeats the word okay, he has heard it before. I decide the only way he is getting to his destination is if I walk him to the front door, which turned out to be true. We have to navigate five blocks of shouting, abusive drunks, the pickpockets that thrive on them, the cops and their whistles and orders, all the while it looks like he is about to stroke out, and I can tell he thinks I am leading him into some sort of trap (I don't exactly look like an upstanding citizen. I've been told that I look like a burglar or a mugger plenty of times, which in this city is an advantage, as I have never been mugged). He looked so happy when he got there, and I was so relieved. He held my arm and looked in a guide book, when he got to a page and said "Thank you, you are very nice man." I kinda bowed and said thank you and went back to the train stop. The rest of the day sucked balls and tits, the train was late, the bus was late, I missed an appointment, fuck, I hate this city sometimes.