Rank the four Villains.

[Haven Celestii 9,385]

1) Chrysalis - Seems to be the main one who could have caused some real damage around ponyville

 

2)Discord - Did more than the last two, but comes up short when his form of terror is nothing but a bluff. It all looks weird, but nothing bad usually comes from it.

 

3) Nightmare Moon - She's basically worthless as all she had planned was unending night. I'm totally ok with night time, so it wouldn't bother me much. Yes, it would be bad for the crops and whatnot, but I'm sure there is a way around that somehow.

 

4) King Sombra - All he did was laugh. :|

Sure, he has some nice traps set up and that awesome greatest fear door, but other than that, he ultimately did nothing but scare people from afar with his name.

[100 beasts kaidou 321]

Are you guys forgeting he was the only Villain that dint lose due to His idiotity? He lost because he dint have any wings, If twilight or cadence was late he would have whooped ass

[NoirX 4]

Not gonna explain because there really isn't much to explain:

 

4) King Sombra

3) Queen Chrysalis

2) Nightmare Moon

1) Discord

 

There's actually a close tie between Discord and Nightmare. But reality warping beats dark magic.

[Winged Anomaly 47]

1: Chrysalis
I found Chrysalis to be a fascinating villain for a children's show.  Her methods were extreme and her plan seemed dire, but given further thought, her entire civilization is in a state of crisis.  She was doing what she thought she had to to save her people from starvation.  Chrysalis was the leader everypony wishes they had, willing to put her life on the line and take tremendous risks to ensure the survival of her subjects - wonderfully sympathetic.  Fantastic character.

2: Discord
Discord is enjoyable, funny, and a joy to watch, but he doesn't have the same kind of depth as Chrysalis did (barring new information from the latest episode, which I haven't seen yet.  I know, I need to).  He was interesting, but at the same time, he was just... a bad guy, if you know what I mean.  While I could see where Chrysalis was coming from, or even start to root for her, Discord was entirely unsympathetic.  Still, a blast to watch.

3: Nightmare Moon
Nightmare Moon almost took Discord's spot, but I quickly realized that was because of the headcanon surrounding her.  If you think about it, the story that was told in the show, where Celestia is unquestionably the hero and Luna unquestionably the villain, seems a little... too good to be true.  What on earth could possibly prompt Luna to snap like that?  Nonetheless, if you take everything in the show at face value, she is pretty boring, even with the commentary on metamorphosis, apotheosis, and insanity her character subtly addresses.

4: Sombra
Sooooo much wasted potential.  A real pity.  Instead of a real, nuanced villain, we got a cardboard cutout, and a story which only offered tantalizing glimpses at what he could have been.  His two-parter is still one of my favourite episodes in all of ponydom, I just wish they'd done more with Sombra.

[Rainbow Dash Loyalty 1,275]

1. Discord - Discord... Master troll and God of Chaos, you can't really compete with that. Plus he managed to corrupt the Mane 6 and Ponyville, and if he wasn't blinded by his silliness he could of got away with it.
2. Chrysalis - She took over Canterlot, fooled everypony including Princess Celestia, took over their defenses and weakened Shining Armor so much that he couldn't perform any spells. I was actually really surprised the couple managed to defeat her so easily without any problems
3. Nightmare Moon - I really liked the backstory for her, your little sister can really change after you banish her to the moon for 1000 years xD
4. King Sombra - I was so disappointed to see him die in an instant without seeing him for than 10 seconds, I swear he had the potential to be the #1 villain and would of taken over Equestria but instead he just explodes and dies... We don't even know his backstory other than him taking over the Crystal Empire.

 

[Quiles 77]

1. Discord- I have a feeling he is most people's favorite, just a well designed villain who is amusing yet evil at the same time (though one could argue he is just selfish)

2. Nightmare moon, just felt like a real villain to me, but not as good fun as discord.

3. Chrysalis, has no real power, just uses deceit which is cool in a way but still

4. Sombra, how much do we even know about him. Quite boring