Worst Movie in a Series

Batman - Batman & Robin (uh...yeah)
Spider-Man - if we're talking about all the Spider-Man movies, then yes, The Amazing Spider-Man 2
Shrek - Shrek the Third
Toy Story - Toy Story 2 (agree completely, I love all three of these movies, but you have to pick one over the other)
Rocky - Rocky V (doubt many people will argue that)
Mad Max - Beyond Thunderdome
Friday the 13th - A New Beginning (I never even watched past this one, I hated it so much)
Halloween - The third one with the witches
A Nightmare on Elm Street - Freddy's Revenge (as far as sequels, I only saw 2, 3, and New Nightmare)
Child's Play - never watched the sequels
TCM - never watched the sequels
Saw - the most recent one
Evil Dead - 2013 remake, easily
Final Destination - the 5th movie
Scream - Scream 4 (gotta say, I like the whole franchise, but 3 just barely beats out 4 for me, I think)
Insidious - N/S
Twilight - N/S
Hunger Games - Mockingjay Part 1 (I was bored to death)
Ice Age - Collision Course (and they're making ANOTHER one, too!)
MCU - Thor: The Dark World (this sequel is actually better than the first Thor movie. The deal is, I like all the Iron Man movies a lot and it's obvious Winter Soldier blows 3/4ths of the MCU away, so I have to go with this)
Madagascar - Penguins (I'll count it)
Kung Fu Panda - 3rd one (yeah, absolutely)
PotC - On Stranger Tides (no arguments there. But this is one of my favorite series and definitely what made me start to notice Johnny Depp as an actor. I'm still hoping they can give us a halfway-decent installment with Dead Men Tell No Tales)
TMNT - the SEQUEL to the 2014 remake (Michael Bay...bleck)
Austin Powers - Goldmember (still has a few laughs, though)
Rambo - the fourth one (you don't have to feel pressured to see it, pal)

I'll spare you my own additions this time around.

"We're not too old for this sh*t!" -Riggs and Murtaugh, 'Lethal Weapon 4' (1998)

I can see you have some of the same choices as me, which is cool. Also, I have seen the new Rambo just recently lol. I thought that TMNT: Out of the Shadows was slightly better than its predecessor. And yes, Penguins of Madagascar is hands down the weakest Madagascar film, it had no spirit, but it was still kinda decent, still not as good as the first three.

I never really liked any of Rambo's sequels come to think of it. I was definitely one of the fans hoping Stallone would pull through and end the franchise with Last Blood, but we may never get that sequel now. As far as the Penguins go, they're some of the best characters, but making a movie solely about them is like making a movie just about the minions in Despicable Me. They don't work as well in their own solo film. They need the other characters to work off of.

"We're not too old for this sh*t!" -Riggs and Murtaugh, 'Lethal Weapon 4' (1998)

'Superman IV: The Quest for Peace' was a stinker.
'Death Stalker III'
'The Beastmaster II: Through the Portal of Time'
'Iron Eagle II' and 'Iron Eagle III'

Bond (EON fims) - Die Another Day