I think that takes the crown - why on earth were you playing there?
Mine are a bit pale after that, but there's definitely been a few odd ones. 14 piece latin orchestra on the back of a flat-bed wide enough for one abreast, which meant that as I was on the far left the other end of the band was probably thirty feet away from my position and the entire line was swaying drunkely as we tried to establish eye contact around each other.
Done lots of squat shows which are universally fun but an awful environment - generally no running water and the doors get locked overnight so you have to wazz out of the mailbox. Solids are verboten but there's usually enough chemicals floating around that you couldn't even if you tried...
Last halloween we rented a giant gothic-style deconsecrated church in a town near us for a 'Black Mass' all-nighter. We set up the hall with tunnels herris fencing covered in drop-cloths to create a bit of a maze with hang out spaces in it, and then the band playing directly underneath the tower at the other end, and then spent a few hours filling most of the church with fake smoke lit by portable workers spotlights as the only illumination. Looked incredible but amazingly cold and the reverb was longer than some of the songs. I got to rearrange some of our tunes for pipe organ accompaniment though.