This question was always very tough for me. So better to pick a few perceptions about me:-
My cubicle mate knows me as: A boring musically challenged person (as his taste is rock and I am a die hard ghazal fan)
My collegues know me as: A so so developer who knows a little aplication security :)
My friends know me as: A bragger who knows only to brag about the things, A happy-go-lucky person
My family knows me as: A very sweet creature brought to this world only for them :)
Hope this helps..