I tried to stop myself Horseflesh but I am going to nitpick here. Hopper was cool in Space Truckers but he didn’t play the villian. He was the(more or less) good guy trucker and Charles Dance played the guy who had to start himself “up” like a lawn mower or outboard motor.
Grig, played by Dan O’Herlihy in The Last Starfighter. “I’ve always wanted to fight a desperate battle against incredible odds.”
Willis Davidge played by Dennis Quaid in Enemy Mine.
Khan played by Ricardo Montalban in ST II: The Wrath of Khan. Heartless, cruel, and incredibly cool as hell.
Um…no. 
Avon, from Blake’s 7.
StarvingButStrong: Yes, yes, yes - how could I have forgotten Avon. Coolest of Characters. By far.
When I was twelve, I thought Timothy Dalton managed to survive with coolness intact despite the shitty script and Kermit-skin costume.
Corwin of Amber gets my nod. Louis Wu, too!
Hell, any of Zelazny’s protagonists is at least 50% cooller than anyone else I can think of.
Except, of course, Roland Deschain of Gilead, Gunslinger.
Ricardo Montalban . . he was definitely slick. But . . eh . . the 80s heavy metal hair . . . the chains. No. I liked Khan, but he more psychotic than cool.
Literary characters are excluded, as per the title of the OP. I’ve heard Zaphod mentioned as a literary character, however I’m referring to the Hitchhiker’s TV series.
Would anyone care if I mentioned my cat is named Zaphod?
Another vote for the entire cast of Farscape, but specifically…
Scorpius
first off, his physioligy;
half-Scarran, half Sebecean
Sebeceans and Scarrans are intractable enemies, Scorpy’s mother was used as an “experiment” by Scarrans to see if Sebeceans had any use as “breeding stock”
Sebeceans cannot tolerate extreme heat, it kills them, Scarrans thrive in extreme heat, Scorpy’s Scarran half and Sebecean half ar always in conflict, he must wear an elaborate coolant suit and have cooling rods implanted directly into his brain
Scorpy is obsessed with wormhole technology, as a means to destroy the Scarrans before they take over the galaxy and extermenate all life that isn’t Scarran, he feels any means justify the end, he has no problem using torture to get what he wants
he’s incredibly intellegent and ruthless, yet the way he’s characterized, you wonder if he’s really as bad as he seems, he’s simply trying to protect the Sebeacan race from destruction…
most interesting sci-fi character i’ve seen in a long time…
hey, it’s all I have. I don’t watch TV but for a bit of news, so I haven’t heard of half the shows mentioned here!
Surely the cooles character anywhere, bar none is Mr. Freeze
I can’t believe it took 50 relies for someone to say it
No doubt, for pure cold logic, it’s Spock.
There’s Roy Fokker. Coolest veritech pilot around.
And mad props to Ian Bliss for the Smith-infected-Bane from Matrix Revolutions. Absolutely cool, evil villain.
Whups, I believe you’re right, Baker. It’s been a while since I saw the movie on cable. I’m so used to Hopper playing the bad guy that I automatically thought it was him in that movie. Okay, Charles Dance it is then.
mutters, sweeps away literary nominees from the table (there’s a thread somewhere for you, Jim and Josh)
While Snake Plisken will probably get my vote in the end, I’ll also mention Riddick (Vin Diesel) from Pitch Black and Robbie the Robot from Forbidden Planet. Thhbbbbbppptt!
I’m gonna third the nomination of Zaphod Beeblebrox.
Sure, all these other characters are cool and all, but:
Only Zaphod was so cool as to have another ENTIRE UNIVERSE created, specifically for the purpose of having HIM be cool in it.
Now that’s cool.
Hal-3000 from 2001…
Do computers count?
Yeah, probably Spock. But in the 60s & 70s the Silver Surfer was pretty cool - and quite a few of the Marvel creations back then.
Good God.
We’re this far into this with no mention of Ash from Army of Darkness???
*“Hey Lady, I’m afraid I’m going to have to ask you to leave the store”
“What’s that on your face?”*
Spock isn’t cool. Hell, I’m almost alone in this opinion, but I always thought he was a jerk. Look at how he treats people when he’s in charge…
John Crighton from Farscape.
And good old Zaphod Beeblebrox. He’s just some guy, you know?
Gendo Ikari from Evangelion. Manipulator, underhanded and cunning. Always seen with the sunnies and the gloves (covering burns on his hands). If you’ve seen the series you’ll know what i mean. Easily the best mentor antagonist/bad guy i’ve seen in a sci-fi tv series.
Perhaps not the coolest… but definitely cool…
Susan Ivanova from Babylon 5
“Trust Ivanova. Trust yourself. Anyone else – shoot 'em.”
Humph!
Another member of the Secret Order of Wesley Crusher fans heard from. 