The best / most interesting display I've seen was at a BBQ in Brooklyn. As dusk drew near, I heard / felt a major 'BOOM' exploding somewhere up above. As if by pre-cognitive signal, the garage doors flew open, and the crowd began dispursing boxes of fireworks packed floor-ro-ceiling, wall-to-wall, door to back wall, from the garage to the street in front of house.
They arranged the boxes in a line in the middle of the street, and lit them off. First lines of firecrackers, then roman candles, rockets, etc. For each category, another line of boxes in the street. The rockets provided a few thrills as some launched horizontally motivating spectators to dive behind cars / walls / anything handy. The smoke cloud and smell of burnt gunpowder was unbelievable. Police cars drving down the street just accelerated past so they weren't hit by incoming.
Then the motars came out: 3-4" diameter pipe 3-4 ft long welded to a flat plate that rested on the street. In went the shell, a 'thump', and several seconds later, a major firework appeared way up high (calculate height via Neutonian physics: s = .5g t squared (g = 32.3 ft/sec/sec, and t = seconds), or height =16 * t * t. example: 4 seconds = 256 ft up). This went on for an hour until the stash was all launched. These folks were not amateurs.
Alas, after Guiliani took control of City Hall, there were no more fireworks the next year, and ever since.