Best: the power outage night at Space in 2001.
Late August, Sundays (then "Home") @ Space. Sasha + Sander Kleinenberg on the bill -- note that Sander played a much different style back then, more underground, deeper, less trashy. He had something to prove and was playing LEGIT stuff back then. Positioning himself to be the next Sasha.
While one of them was playing (not sure which one), around 3am, suddenly the power went out in the Space discoteca - everything went out. Lights, music, everything. It lasted for at least an hour. I think Pepe even got on the mic to apologize.
Most people left the room and went to hang out on the terrace. A few folks hung around in the empty + silent discoteca...super bummed and too cross-eyed to move.
After most people had given up, they actually got power working again, and out of nowhere came BOTH Sander and Sasha, who apparently decided to go back-to-back for the rest of the night, since the outage messed up their set times so much.
Sasha put on the first record (80% sure it was Gaelle - "Rain"), the club lights flashed on and went back down, and people were running back into the discoteca.
The vibe in a room when everyone starts at EXACTLY the same moment and the same energy level, is just unparalleled. They went on to play B2B until 9 or 10 in the morning. I want to say it was at least 5-6 hours.
Truly the greatest B2B I've ever seen.
Side note: am sure others have similar stories of the magical energy in a room when a club night gets interrupted and then re-starts 30, 60, 90 minutes later. There was a legendary night at Twilo, one of its last before it shut down, where a fire alarm went off and they had to evacuate the whole club onto the street...in the middle of NYC winter. I think it was PVD playing an all-night set. When they let everyone back in, it was the same phenomenon - everyone starting their journey at exactly the same place, and so much energy. I've met several people who were there and still testify it was one of their greatest clubbing experiences.
But for me, Sasha + Sander at Space, the night the power went out.
you can listen it here: 
