Below are two videos from the greatest concert ever played by my favorite concert band ever, Pearl Jam. (Thanks for the inspiration, erin.)
In September 1998, near the end of a tour, Pearl Jam played Madison Square Garden for three nights. For several days leading up to these concerts, a group of fans decided they wanted to hear Pearl Jam play a song called Breath. It hadn't been done live in about 4 years, but it's the favorite song of a lot of PJ fans. (It's now my favorite too, but I didn't know the song in 1998, even though I was well on my way to becoming a die hard fan.) So this group used the early days of the internet to create a whole campaign to get them to play it live. There were signs and everything.
And then, on the third night, when everyone was about to give up, Eddie comes back from the encore break, sees all the signs, and says: "You know, we come up here as a collective band and we give and we give and you just fucking want more ... and you know what? You deserve it. This is like some kind of organized religion here; I've never seen anything like it. Do you see what's happening? ... the third night in a row, right? Well, fuck you. We're gonna play it!" And then he does...and the crowd goes nuts. (Hear the speech here, but the link will only work if you copy-and-paste it rather than clicking it.)
And the show only got better from there. Eddie had some pretty incredible acrobatics at the end of the last song, Alive.
If you only have time to watch a bit of the video goodness here, watch that second video between the 4:30 mark and the 6:00 mark.
I first heard Breath live about 2 years later (and, in the end, at 2 of the 4 PJ concerts I attended over the years), and it was well worth the wait. PJ really loves nothing more than to play live, and the fans want nothing more than to hear one song. When it happens, it's a perfect moment.