Well, virtually everything I can think of has been mentioned, and I mostly read SSSS and Lackadaisy anyway...
But, for those who like Pokemon, there's a niche I don't think anyone's mentioned yet: comics based off the Nuzlocke challenge. There are quite a few out there, and some of them are good enough to be great comics in their own right. Here are a couple of my favorites:
Folded is absolutely lovely, with a beautiful simplicity to both the story and art. It's also made by a Finnish artist!
Goddamn Critical Hits is mostly a comedy (and a very funny one, in my opinion), but the depth of character development is actually pretty impressive. The art has also gotten
really good over time.
If this niche genre appeals to you, I'd also recommend
The Long and Winding Road (the art gets better if you stick with it!) and
Ken's FireRed Kick@$$ Mode in the comedy department.
Mon Amie has a good blend of humor and drama, and although the art gets a bit repetitive, the writing is quite good.