I read all of these, and probably more. If it is on this list, I think you would like it. You will probably see bits and pieces of inspiration that I have taken over the years... though I can't pinpoint much of it myself.
Please note that I am in no way affiliated with any of these, other than the fact I like their work. The comics I would suggest the most would have to be Homestuck and Mokepon, in case it isn't obvious from the descriptions, but they are all very good.
An adventure/fantasy story about a demon hunter named Kiran (which happens to be a demon), a kid named Teeko who got shrunk by a messed up spell, and the people they meet along the way. A well put together story by Varethane. Grey-scale, but very well drawn.
In case the name didn't tell you, the main character is a Doctor, and he is a ninja. A lot of really, REALLY strange stuff happens in this comic, but at the same time it makes sense in a strange way in-setting. Not many comics can have Irish ninjas, a clone of Benjamin Franklin, Gorilla assistants, and robot-Dracula into an oddly cohesive mix. It is awesome. The author, Christopher Hastings, has other projects as well, including some of the recent Deadpool comics.
El Goonish Shive
This one goes all over the spectrum, tone-wise. Usually it is a light-hearted comic about magic, shape shifting, and miscellaneous shenanigans. However, there are also times that things get significantly darker, to the point you might wonder if you are reading the same comic. The art improves substantially from the first pages to the last, so don't let that turn you away.
A fairly standard comic about a set of adventurers in a Dungeons and Dragons setting... except for the fact it is from the perspective of the goblins.
A fantasy story set in a strange school that teaches the existence of both magic and science.
Homestuck... Where do I begin, to try to describe the behemoth mostly-webcomic, sometimes video, sometimes game, that is known as Homestuck? If you have the time, and don't know what it is, I would strongly suggest looking into it. It starts out as a nonsensical game that four friends are playing, where the game directly affects real life. As it progresses, it becomes more and more of an epic tale... I don't mean "epic" as in awesome, I mean "epic" as in: multiple times I have seen it compared against the Illiad with respect to length and scope. It doesn't look very deep on the surface, especially for the first couple acts... Just wait.
Remember the first Pokemon games? Red and Blue? No, not Fire Red, Red. The original. This is a parody story, that follows a trainer who would honestly just prefer to stay home... but can't. This all takes place some time after the events of the game, using the original games as cannon (with exceptions for a few characters who have traveled).
Rhea dies, and since the scales of her live balanced only a little towards evil, she is sentenced to the least of the rings of hell. There, she meets a mentally damaged demon. They eventually break out, and meet a warrior angel cursed to occasionally turn into a bunny. Usually rather funny.
Fiona Dae was a relatively normal person before she sortof accidentally got stolen from our world to an alternate where magic is commonplace. At this point she is mostly just trying to get back home, or at least find a place where she can just belong again.
If an evil mastermind gives you two options, join or die, which do you choose? Adventurer/Alchemist Sebastian was given this choice, and now he is playing for the bad guys. This is his story.
A good gag-a-day style webcomic for all things geeky.