A: Cards (Actions) that end your turn immediately if you play them:

Brain Transference: Star Fluxx
Time Portal: Star Fluxx
What Do You Want: Star Fluxx, Oz Fluxx, Doctor Who Fluxx
I’ll Be In My Bunk: Firefly Fluxx (This card does not specifically say that your turn ends immediately, but you certainly can’t continue your turn if you “Excuse yourself from the game and leave the room for a few minutes.”)

Cards (Rules) that end your turn immediately if you choose to utilize their ability:

Swap Plays for Draws
Get On With it

Since Rule-based Free Actions are optional, the player is not obligated to use their power, so simply putting them into play does not end the players turn immediately. However if any player chooses to use the powers of these cards, the effect is simultaneous with their turn ending immediately. Most notably, this means that if you draw any Creepers with your draws from Swap Plays or Get On With It, you’re stuck with them until your next turn, even if there are conditions which allow you to trash or give them away on your turn. Your turn ended immediately with the draw, so that window is over.