Q: What cards have effects that include ending my turn immediately if I play/use them?

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 “free” Rule-based 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 concludes with their turn ending immediately.)