Which villains return do you think was the most effective

[burrunjor]

Surprisingly even though it was all down hill from there, I think the Master. His first episode Utopia is an absolute classic and the build up when they bring him back, and Sir Derek Jacobi's performance are absolutely perfect the way he switches from kindly old man to vicious sociopath. Also I like Murray Gold's score there. It suits the scene and the cliff hanger is genuinely brilliant.

To be honest though they shouldn't have left the future setting. 

I have mixed feelings on the Daleks first story, even  if they were handled the best out of all classic villains. The Cyberman one I've gone a bit back and forth on, but even then their actual return isn't as special as the Master. The Sontaran two parter is excellent, but again their actual return in the story itself isn't quite as spectacular. 




Sorry I was lost in Freema Agyeman's unearthly beauty for all of that there, LOL but from what I remember that is a classic moment. 

[rushy]

The Daleks' return in the Eccleston era was fantastic.

The Master was very well handled until Missy.

The Macra, but only because I don't like their original story to begin with, so seeing RTD dumb them down into monsters felt cathartic.

The Sontarans had a very solid comeback, arguably their best story since Time Warrior. Similarly to the Master, though, Moff immediately turned them into a joke. I hear even Chibnall handled them better.

The Silurians were handled decently in "The Hungry Earth", even though it was just another variation of the same old idea they've used in every other Silurian story.

The Great Intelligence, but only the fact that he's played by Richard E. Grant. The story itself was shit.

The Ice Warriors have been respectable in both NuWho entries. Especially Empress of Mars.