What was the worst of each series???

[Sploid The Noid]

There is always one bad entry into every good series.  Aliens 3, Robocop 3, Batman and Robin... etc.   What were some other memorable doozies in otherwise great series?

[Cloudio]

Nightmare on Elm Street part 5
Friday the 13th part 9
Rocky 5

[Offthewall]

Personally Nightmare 2 was my least favorite

[Steven Millan]

       The Sequels That Stunk.....
        Porky's II:The Next Day
        Every Halloween and Friday The 13th. Film After Part 2
        Alien 3,and Alien:Resurrection
       Star Trek 2:The Wrath Of Khan
       Star Trek:Generations
        Nightmare On Elm Street 3 and 5
        Texas Chainsaw Massacre:The Next Generation
        (a.k.a.:Return Of The Texas Chainsaw Massacre,TCM 4)
         Pumpkinhead 2
         Every Howling Film After Part 2
         Every Andy Sidaris Film After "Picasso Trigger"
         Phantasm 4:Oblivion(the film where Mike,Angus,Reggie,Bill[a.k.a.:Jody],
             and Don Coscarelli threw all of their pocket change on the table,and
             based P4's budget on it)
          Police Academy Parts 5,6,and 7(the Moscow one)
          Deathstalker Parts 2 and 3
          ANY Sequel Directed by Jim Wynorski or Albert Pyun
          Inner Sanctum 2

[Orga Hades]

-anything after Leonard Part 2, (excluding, of course, Leonard Part 6.)
-Poor White Trash 2
-Real Sex 7 (the one with Janet from Three's Company)
and
-the fourth Doctor

[BlackAngel]

Ghostbusters 2
Mortal Kombat: Abomination
The whole TMNT series
The whole Power Rangers series

[Cloudio]

That may change as soon as the third Mortal Kombat film comes out.

[StatCat]

The 2 return of the living dead sequels come to mind first.

[Xu Xing]

-Yeah, return of the living dead 2 especially sucked, 3 was bad, but not AS bad as 2.
-House 3 & House 4 (I think House 3 was released under the name "The Horror Show" and "Horror House")
-MIB2

There were actually other Leonard movies?  I thought there was only Leonard part 6...