Favorite Nighttime Spectacles at a Theme Park

Disneyland's Fantasmic!
MNSSHP's Boo to You Parade
Main Street Electrical Parade
Bohemian Rhapsody at Hard Rock Park
Electric Ocean at Sea World San Diego
Apollo 11 50th Anniversary at the National Mall (Washington, DC)
Dark Arts at Hogwarts (USH)
Dollywood's Sweet Summer Nights

Illuminations - Reflections of Earth.
The Main Street Electrical Parade as I remember it from being a child.
Disneyland's Fantasmic. The version at Hollywood Studios is just a shadow.
SeaWorld Orlando's Christmas Quadrupedal-header(from about 12 years ago) - The Shamu Show, The Sea of Trees as you walk to the Ice Skating show in the Bayside Theater followed by Fireworks. It's absolutely amazing.
Paint the Night at DL.

Marathon of Mayhem at Halloween Horror Nights

In no particular order and not counting parades:

IllumiNations (original, not Reflections of Earth)
Disneyland Forever
Dark Arts at Hogwarts Castle
World of Color (pretty much all of them)
Rivers of Light (original)

Aquanura met een zachte G at Efteling
Ignite at SeaWorld Orlando's Electric Ocean
Marathon of Mayhem at HHN 29

Disneyland Fantasmic(2017)
Main Street Electrical Parade
Dark Arts at Hogwarts Castle
World of Color

Main Street Electrical Parade
Electrical Water Pageant
Cars Land Sh-Boom Neon Lighting
The Osborne Family Spectacle of Dancing Lights
Tree of Life Awakenings
Spaceship Earth Beacon of Magic
IllumiNations
Wishes

Thing is, often didn't see a lot of nighttime shows as would hit Pleasure Island after parks.

But hard to top Illuminations in all its forms.
Main Street Electrical Parade
Osborne Family Spectacle of Dancing Lights
Magic Kingdom Holiday Fireworks
Fantasmic
And yes even Spectromagic

The numerous spotlights at PI and the midnight countdown celebration were awesome!

In no particular order...

Disneyland's Fantasmic (probably my favorite nighttime spectacular)
Remember...Dreams Come True
Happily Ever After
Main Street Electrical Parade
Paint the Night
Electric Ocean
Holiday in the Park at various Six Flags properties
Small World Holiday's Facade (yes, I'm bending the rules here)

I'll also throw in that World of Color and IllumiNations, though not bad, are among those I consider to be more overrated.

Fantasmic tops them all.

Sweet Summer Nights at Dollywood this summer was pretty good. The drone portion of it (albeit very short) was great, and I think if Animal Kingdom is still looking for a nighttime show, that is what Disney should pursue.

UPDATE: The big beautiful barges in World Showcase Lagoon still do not have their fountains on during the day. Nevertheless, it’s really pleasant to see how well the barges blend in with World Showcase. Without a doubt, the barges are the best addition to EPCOT since the Sorcerer Mickey Wand stood high above Spaceship Earth in the early 2000s. Well done, Disney!

I'm going truly old school with mine:

The original, full-length Main Street Electrical Parade that played at WDW in the '70s/'80s

A Little Night Magic -- the Shamu show at SeaWorld Orlando circa 1987-89. I bought the soundtrack album to the movie Ladyhawke solely because of the fact they played it during that show.

1982 - Working crowd control (front row, unobstructed) as a cast member and seeing the Candlelight Processional coming down a darkened Main Street USA from Cinderella Castle and assembling at the train station in Town Square.