I like a rehearsal where the drummer turns up in a foul mood cos he's had an argument with his Mrs, then the guitarist turns up drunk with no leads.
After I've helped the drummer set up and lent Mr Guitar some leads I'm then most gratified when the drummer starts taking out his frustration by hitting every drum as hard as he can, with GuitarMan playing his best Hendrix impersonation at a different speed at absolute full volume. To be perfect, the singer should then turn up saying they can only stay for 1/2 an hour, at which point guitarist nips out for a 10 minute smoke break, coming back smelling of skunk and unable to stand.
We'd have time to play 4 or 5 songs, but wouldn't get past the first one because:
a) the singer thinks it should be faster
b) the drummer thinks it should be slower
c) the guitarist is sick on my pedalboard