Completely released and translated, unless stated otherwise.
Doubt. Nice and short. Murder and mindgames. Licensed and published by American publisher. 2 omnibuses.
Judge. From the same author. Seems to have similar theme as Doubt. Haven't read it yet though.
If you're a fan of Urasawa Naoki's(Monster's author) work, definitely read Pluto and 20th Century Boys + 21st Century Boys. 20CB+21CB are much longer than your preferred length, but definitely worth it. Licensed, fully published. And also Master Keaton it's not licensed and fan translation is at around 3rd volume. Also 36(?) episodes of anime. Billy Bat is still ongoing. Wasn't licensed by Americans. Currently at 100+ chapters. Urasawa Naoki gets my personal "Must Read" stamp of approval.
Superior Day. Korean web-comic(long color pages). About serial killer. Very good. Fan translated. 40 chapters.Must read
Melo Holic. From authors of Superior Day. Rom com with a twist. Gooood.Must read
Ai-Ren. Masterpiece. Cute, tragic, heart warming... plus mildly distopian future. I doubt it was licensed by American publisher.Must read
Liar Game. Deception and mind games. 300+ chapters. Sadly incomplete and on hiatus.
Mirai Nikki. Fun and psychotic. 12 volumes total. Licensed but dropped after 10 volumes. Fan translation is complete.
Bloody Monday. Terrorists, spies, sinister plots and betrayal. First part - 11 volumes. Licensed and fully published. Part 2(8 volumes) and 3(4 volumes) were not licensed, but fan translations are complete.
Gantz. 30+ volumes but very fast and nice read. Graphic violence and very nice art style. It relies more on it's visuals than on text.
Can recommend more if you tell more about your preferences.