Spock is the half-vulcan half-human first officer on the USS Enterprise in the Star Trek franchise. Played by Leonard Nemoy in the original television series, he provides to the series an "impartial view of the human condition." Named on the the 50 Greatest Television characters by TV Guide, he is a still-loved character, revisited with positive reviews in 2009 alternate-timeline Star Trek movie.
I can never claim to have been a Star Trek fan only because I was never a fan of science fiction in general. My primary knowledge of Spock is that he is half of the pairing that gave birth to the phenomena of slash fiction in the United States- that is, the act of creating fictional "fan" works featuring a relationship between male characters that do not have a romantic relationship in cannon.
I can also never claim to not be a fan of slash fiction in general, so there's my big dark secret, huh?