Point of order your Honor the OP, but since you were regretting using ‘Iconic’ in the original post, and you didn’t add a supplemental text to the poll, what were you thinking of for your definition of iconic.
Because you did clear up that for your POV, super heroes, even scientific ones, did not qualify as scifi. Which is fine, and you didn’t include any in the poll. But knowing your initial intent would make the debate more interesting to me at least.
Not to put you notice, just curious.
Michael Moorcock’s Eternal Champion beat Doctor Who to print by a year. Two years, if you back date it to the first Elric story. Even longer, if you date it to the first time the Doctor regenerated, and not the premiere of the show.
I think I probably should have tried something more along the lines of “Best Sci-Fi character of these listed”.
Iconic has brought up a different criteria, but that’s fine, this has been fun anyway.
Ah! If that had been the title, I’d probably have further added to the ‘Spock’ pile then. Star Trek has a lot of technobabble, but it’s still much closer than Star Wars to scifi IMHO (wars have been fought over less…).
And while I like the Kirk, the Doctor, and Ripley (and Alien is closer to horror in space than scifi for that matter), Spock is still ‘best to me’.
NOTE TO SELF - Do not mention this poll to my wife, she was determined when she was young that she wanted to marry both Spock and Luke Skywalker and have tons of Vulcan and Jedi kids. Lucky for me she was willing to settle for less 
Aye but widely known is required too. 
“Best” would get many of us disagreeing about its meaning too! Tough crowd.
I would wonder how people would react to “most important” culturally. I think Spock had the biggest cultural impact.
I liked “most iconic” because that’s semi-objective. There’s something to actually discuss with “most iconic.” You can’t debate “best.” “I like this better.” “No you don’t!” Meh.
For what it’s worth, I asked my mom, who doesn’t particularly follow science fiction (though she picks up some from osmosis from me), and she said that Spock was more iconic than Vader, because he’s been around longer.
Still going to stay with Vader. Spock was culturally impactful for geeks. Vader was culturally impactful for everybody.
Spock helped launch geek chic. The science hero was not IMHO his essence, agree with @Pleonast on that, his mixed origin identity conflict was, but his science hero helped set the stage for the cultural elevation of the science nerd that followed. Vader no.
I voted Spock, but in retrospect I did so on a super-nerdy pedantic quibble, and I realize this board frowns on quibbles, pedantry, and nerdiness, so I apologize. I tend to think of Star Wars as more mythological, more space fantasy, than science fiction, whereas Star Trek is the quintessential science fiction franchise; so in that respect Spock is more iconically science fiction, even if he’s not as iconic as Darth Vader.
Of course, the best science fiction show is The Expanse, but that’s just too objective to argue over.
Why did he wait 40 years to do it, then? Geek chic is very much a late-90s-into-the-noughties phenomenon.
Hey, some of us were geeks before it was cool!