Tower of God and many Korean Webtoons in general. They combine the artistic freedom of webcomics with a heavy influence of Anime, Manga and Manhwa in a chapter-long vertical, full-color strip. Tower of God in particular excels in tight story-telling and World Building, using interesting games and tests to flesh out characters and advance the plot. The story follows a boy who chases his only friend into a mystical place called the Tower, where he is told that if he wants to find her, he must reach the top. He then has to compete with many other people for the right to ascend to the next floor, because apparently any wish can be fulfilled upon reaching that place. During his travels he accumulates a bunch of comrades and they are all pretty awesome by their own right. Take for instance a noble that likes to scam his way through the tests and loves to bend and use the rules to his advantage or the giant bipedal alligator that spouts badass line after badass line. But the best thing about the series is how unpredictable it can get. Especially in the latter chapter, after everything has been established, the author loves to play with the perception of details so that whenever a surprising twist comes, it makes perfect sense.
minus. Great homage to old newspaper comics with a thought-provoking premise. Unfortunately, it's practically unheard of.
Between The Lines. It's a comic about 2 transexual teenagers who come from messed up families, and find acceptance in each other. It's based off the experiences by the author, and it will make you feel the hardships Shay and Dani go through.
Carpe Chaos: Space Opera with gorgeous art, intelligent mature writing and is building a complex universe with thousands years of history.
Archipelago. It... it kind of defies description, actually. It may not look very impressive at first, but undergoes massive Art Evolution and the story itself is very compelling. Perhaps best described in the words of the comic creator: Here you will meet demons, Ravens, crazed pirates, and were-sharks. Enjoy the ride!
Law Of Purple is an excellent sci-fi webcomic that makes a statement about social issues such as racism and homophobia while still managing to be absolutely hilarious.
Prequel is practically a must-read for any fan of The Elder Scrolls, and still a pretty good idea for everyone else. The story centers on Katia, who might be the most pitiable Kadjhit in all of Cyrodiil, as she attempts to make a new life for herself, and fails. The art is surprisingly good, and the audience can submit commands for Katia to consider, which she will, in comic. Be warned, it can swing pretty heavily from lighthearted humor to bitter depression and back in an instant, but don't let that dissuade you.
Shadowbinders is a steampunk fantasy about a girl named Mia who finds out she can cross dimensions to some place she's been dreaming about, when looks through some heirlooms of her grandfather given to her by her grandmother and finds a very special ring.
Suppression is a 3d Webcomic about a town called Ebon Creek being struck with a horrible plague, giving people odd types of powers before possibly turning them into monsters. It updates twice a week and has a rather large cast of characters and a very interesting story.
Domain Tnemrot is a low sci-fi story about gladiatorial games where the fighters have super powers. They fight each other, trying to stay alive while they plan their escape from captivity. Ensemble Darkhorse characters abound.
FAMIB has been around since 2001, it's in an Alternate Universe and about a boy and his dragon, horribly subverted as that same dragon adopted him with after murdering (all but one) of his family. The other group of the Two Lines, No Waiting are special forces / agents of the government looking for the dragon, among other duties.
Let's Ask Violet- The premise is about a college student answering questions. Sometimes, her answers can be insightful, while others can be hilarious, depending on the asker. When she's not answering questions, she deals with her personal life such as relationships and her roommates. Definitely something I'd recommend. I learned about it when Linkara tweeted about it.
The Less Than Epic Adventures of TJ and Amal by E.K. Weaver follows the form of a typical Road Movie. It features the budding romance of the title characters in the most nerdy, believable way possible, as well as some superb dialog, well-crafted characters, and great art that pays special attention to the little details of life.
Crankrats is a steampunk series with a decent amount of world building and a ton of characters.
Zoophobia is a Webcomic about a teacher that has the titular zoophobia and has to teach a class full of mythical and anthropomorphic animals. The art is great, and the story isn't half bad either, but the comic only has about 500 or so people who follow it.
''Necropolis is a fantasy series involving an Action Girl named the Third Sword who fights undead creatures. Has a deliciously Hellboyish feel to it. Unfortunately, only a few pages of the comic proper as well as a few preview pages are out, but everything's so promising that it already deserves a fanbase.
Dramacon by the queen of Original English Langauge Manga, Svetlana Chmakova. This work features a solid story, effective characterizations, and art quality on part with many classics of this genre.
Color Blind is a fantasy comic about five middle school kids who find a colorful fantasy world with interesting creatures and a dark underlying conflict.
The Veligent is about Kade and his misadventures in the highly unusual fantasy world he lives in as he gets to work on his new job.
Distillum is a series by Sarah "Pickles" Dill and tells the story of Rob, a young man with unusual psychic abilities, as told by his friend, Jamie. After they save the life of Kavitha (who was supposed to die), they're dragged into the world of the "Distillum" by the ever-cranky Sidney.
morphE is something completely different from other webcomics. It's made to "play" like a visual novel with some mild interactive elements and completely animated updates. It starts a little basic but so far it has run for a year with 200 updates. It deserves attention for its unique style and ambition if nothing else.