Mostly from the Player's Handbook. TO my knowledge, all the iconics listed in the PHB are
Krusk the Half-orc barbarian
Devis the half-elven bard
Jozan the human cleric
Vadania the half-elven druid
Regdar the human fighter
Tordek the Dwarven Fighter
Lidda the halfling rogue
Naull the human wizard
Kendrick the human thief
Nebin the gnome wizard
Mialee the elven wizard
Hennett the human sorcerer
Alhandra the human paladin
Ma'varkith the human psychic warrior from the psionics handbook
Ialdabode the human psion from the psionics handbook
Alexandra the human psion from the psi handbook
Kazak the dwarven psion from the psi handbook
This is more of a .sig question. Sorry about that!
Handmade, mostly. I don't remember the poster who started it, but once it began (with some of the iconics), people branched out on the joke, most posters intentionally giving their "banners" the same look as the first originals. Now, the joke has kind of mutated, and we have everything from Iconic Familiars, to Iconic Posters, and Iconic Beer Mugs.
I made mine with my |33t M$ P41n+ skillz.
Just took a picture, scaled it down, added text.
As to where I got it from, well, there was an old TV show called "The Prisoner" back in the 60s about this guy called "Number Six" who was being held prisoner in "The Village", yadda yadda yadda. Anyway, the badge that identified him as Number Six is the Penny Farthing in my sig.