I'll read just about anything, except gag-a-day comics. Although my favorite stuff to read is horror, gore and/or tragedies, which is super rare in the webcomic community. Also stories with mature, "taboo" themes are nice, anything with those as a subcategory is right up my alley. I'll read romance, but I'm not a fan of it, the genre is just good for turning your brain off and looking at nice pictures.
As far as what I like to write, I don't really know yet, I only have a failed practice comic and my current one to go off of. My old attempted story was a coming of age/slice-of-life type of thing, my current comic is a psychological drama/slice-of-life with some heavier themes. The stuff I plan to make in the future are combinations of sci-fi, fantasy and cosmic/gore horror, which is all completely divorced from my current project.