* IAmNotSpock: Averted with Keanu Reeves, played straight with Alex Winter.
* TheOtherDarrin: The princesses are played by different actresses in the sequel.
* ScrewedByTheLawyers: Creator/KeanuReeves and Alex Winter are both willing and eager to make a third film, a screenplay has been completed and gone through several rounds of rewrites, and there is a production company willing to front at least part of the budget. Unfortunately, none of these are with the company that owns the actual rights to the franchise and everything has fallen apart over who pays for what and gets how much of the resulting pie.
** SugarWiki/MostTriumphantExample (partly)