Think back: Who's your fav one-time-appearing villan?
 

Rao Vantica here.

Re: Think back: Who's your fav one-time-appearing villan?
 

Admiral Leyton.

Re: Think back: Who's your fav one-time-appearing villan?
 

Magnificent Ferengi Vorta

He is the worlds forgotten Vorta, the one who searches to destroy.

Re: Think back: Who's your fav one-time-appearing villan?
 

Kilana the Vorta.

Re: Think back: Who's your fav one-time-appearing villan?
 

Commander Lovok, who made me start paying attention to Leland Orser.

Re: Think back: Who's your fav one-time-appearing villan?
 

Keevan, the Vorta from Rocks and Shoals.

Re: Think back: Who's your fav one-time-appearing villan?
 

The Lethean that tried to buy bio-mimetic gel from Julian Bashir.

Re: Think back: Who's your fav one-time-appearing villan?
 

Love Kevan. My #2.

Re: Think back: Who's your fav one-time-appearing villan?
 

Grathan Tolar....

Re: Think back: Who's your fav one-time-appearing villan?
 

Gul Darhe'el.

Re: Think back: Who's your fav one-time-appearing villan?
 

Definitely Entek!

Re: Think back: Who's your fav one-time-appearing villan?
 

I believe Keevan makes a second appearance...

Re: Think back: Who's your fav one-time-appearing villan?
 

Taking villain to generally mean the "bad guy" my favourite is Cal Hudson.

Re: Think back: Who's your fav one-time-appearing villan?
 

Third Romatiklan, by a wide margin, assuming Keevan doesn't count.

Rocks and Shoals is one of my favorite episodes.


I also like Mareel in Invasive Procedures. She beat up Kira - who attacked her - without breaking a sweat, and rubbed it in a couple scenes later by asking her "are you ok?" in a mock-caring, motherly tone upon seeing Kira try to walk across the room with obviously sore ribs.

Re: Think back: Who's your fav one-time-appearing villan?
 

No Altovar was the guy who tried to buy the Gel and psychically attacked Bashir forcing him into a deadly nightmare where Altovar haunted him. The real Altovar was captured almost immediately after the attack in the episode Distant Voices.

Grathan Tolar was a criminal on Kingon death row who Sisko spared to make a Holo Recording on a Cardassian Optilithic Data Rod. The rod was obtained by Garak who paid for the rod using Bio-Memetic Gel given to him by Starfleet over Bashir's objection in the episode In the Pale Moonlight.