I have a story that falls into a couple of your categories. Both GREAT trade stories and ALSO very much proved that great, nice people do exist in this hobby.
When I first joined this site, I introduced myself in the New Members forum. I told my story of who I am, where I am from, how long I have been collecting etc etc. I also mentioned my goals of one day FINALLY pulling or owning in one way or another my first Aaron Rodgers and Brett Favre auto cards. I told a brief story of my former card collection either being stolen or destroyed by a very devilish person.
I was pleasantly surprised to see 2 PMs from two members who I will not name at this moment. One freely offered to send me some Green Bay Packers cards (which I PC, and they are my favorite team.) He even hinted that there may be relic or auto cards. I offered him a Demarco Murray RC that was the one and only card that I owned that he PCs.
The second offered me some cards freely as well, but would not allow me to send him anything in return. He told me he had too many cards as it was and I was doing him a favor in taking the cards he was offering.
Well, the cards came and I was TOTALLY blown away. SO many awesome Packers cards. All kinds of Aaron Rodgers among others. Even a Brian Brohm relic card! I was VERY stoked! I could never imagine this happening to me...I knew I would trade once I got on this site but I never thought one person, let alone two would offer me Packers cards for nothing.
So, in closing I gave up a DeMarco Murray card for a BUNCH of PC Packers cards including a relic. This has inspired me to "pay it forward" as best I can. I want to be able to put together a nice lot of cards of certain teams so that I can offer some people something nice for their own PCs.
I am currently putting together team lots to send out to fellow members, though I am on a budget and cannot build these lots very fast. I hope to give more people the same kind of warm welcome that I got!
Green Bay Packers fan since 1994. Always looking for Aaron Rodgers,Eddie Lacy, Clay Matthews, Jordy Nelson, and Favre (Packers only.)