Most disappointing sequel or prequel you've ever seen?

[ditcin]

Jurassic Park - Lost World
Jurassic World
Die Hard 4
Die Hard 5
Lethal Weapon 4
Jaws 2

[Galactus]

X-Men: The Last Stand
Hellboy: The Golden Army
The X-Files: I Want to Believe
Aliens Vs. Predator: Requiem
Indiana Jones and the Kingdom of the Crystal Skull
Spider-Man 3
The Godfather Part III
Rocky V
Shrek 2
Shrek the Third
Shrek Forever After
Quantum of Solace
Dumb and Dumber To (The prequel is better)
Taken 3
Fantastic Four: Rise of the Silver Surfer
Beverly Hills Cop III
Men in Black II
The World Is Not Enough
Blade: Trinity
Scary Movie 3
Scary Movie 4
Scream 3
Scream 4

[avs commenter]

Ghostbusters 2
Meet the Fockers
Terminator Geneisis
Phantom Menace
Fletch Lives
Batman Returns
Teen Wolf 2
Predator 2

[Lord Method Man]

Prequels:
Alien Covenant
Star Wars Prequel Trilogy

Sequels:
Independence Day: Resurgence
Rocky V
Star Trek V
Star Trek Into Darkness
Star Wars The Last Jedi

Umm, both??:
Terminator Genisys

[sanriel]

The Descent: Part 2 (2009)
The Ring Two (2005)

[Juels Winnfield]

In terms of expectations:
The Last Jedi