I read a lot of webcomics; there's a high turnover, as I keep adding new ones and removing old ones from the list, but I think I'm currently over 60 webcomics regularly read…
Of course, most of the better ones have already been named (so if you need to make a decision, consider my additional voice in favor of Gunnerkrigg Court, Ava's Demon, Nimona, Namesake, Skin Deep, Rice Boy and other comics by Evan Dahm, Monster Pulse and Cucumber Quest).
But there's also a couple of very good ones I haven't seen mentionned yet, so:
Poppy: The adventures of an opposum mother named Poppy and her little girl Lily, who live in a world of fantasy and magic; unfortunately, in this world, opposum are the only intelligent species who lack magic, and as such they are strongly discriminated against, and often outright persecuted; fortunately, Poppy has lot of raw enthusiasm and is ready to take on the world to protect her daughter no matter what. She also has the physical strength of a dozen tyrannosaurs. Really.
Fantasy, humor, lighthearted stories with a dose of social issues and dark thematics. Updates once a week but with several pages.
The Property of Hate: When a strange man with a tv for head appears one night in the bedroom of a young girl and asks her if she wants to be a hero, she jumps at the call without hesitation. She subsequently finds herself in a strange world where concepts have literal, physical incarnations. Lies, doubts, ideas, fears and griefs are all creatures that walk around and, as she quickly finds out, can and will threaten you —it doesn't help that the tv-headed-man, who claims to act as her guide in this weird reality of concrete abstracts, turns out to be a rather cynical and blasé man with hidden motives in his actions.
Surreal fantasy with clever dialogues and writings, and loads of actually-well-used puns. Updates once a week.
A few other comics that might interest you:
Derelict; post-apocalyptic in a world that mostly revolves among boats and coastlines; usually updated once a week, but missed weeks happen often.
Ignition Zero; urban fantasy with queer and asexual sensibilities; updates once a week.
O Human Star; science-fiction (robots, cyborgs) with gay sensibilities; seems to updates every two weeks with one or two pages, not sure.
Monsterkind; urban fantasy, lighthearted social drama, deals with discrimination and segregation; theorically updates once a week but often irregular
Monster pop!; see Monsterkind; the comics are unrelated, but the premices and thematics are really similar (so are the update schedules).
Tripping over you; boy love (safe for work) and slice-of-life; updates twice a week.
Spera; anthology fantasy (different stories by different authors about the same characters); unfrequent updates, but each updates brings either a complete short story of a dozen pages or more, or a whole new chapter in the onging major story.
Iothera; science-fantasy with queer thematics (NOT SAFE FOR WORK); updates one a week in theory, often more slowly in practice.
Witchy; fantasy, updates once a week.
The Intrepid Girlbot; science-fiction and humor without dialogues; updates once a week.
The Last Halloween; urban-fantasy, horror, humor; updates once a week but pages are pretty big.
Astal Aves; fantasy with lots of original ideas and interesting universe; updates once a week.