Commander Keen, a cop (is he a specific cop?), ?, Lara, Lara, Charlie Caplain or Jack the Ripper?, Ronald McDonald
?, Darth Vader, Storm Trooper, Boba Fett, Cpt. Zapp Brannigan, Homer Simpson
Duke Nuke, ?, Mario (fire flower powered up), Link, Beast (from Disney), one of those Tronn bots
Snow White, Robin Hood, wizards..., Hunchback and the gypsie (Disney style again)
?, ?, tencacles from Maniac Mansion (or Day of the Tentacle), Jessica Rabbit, Marvin (Hitchiker's Guide), Yoda, Chewbacca
And might I say, I'm most envious of your ability to render so many instantly recognizable likenesses with so few pixels. Well done.
(I deliberately didn't read other posts so as to avoid "cheating".)