Only gonna talk about novels because I don't know much about comics.
Here's a list of the sites that I know of that I would consider using:
royalroad
moonquill
inkitt
scribblehub
swoonreads (this seems quite promising, but they seem to be looking for completed manuscripts)
there are other smaller sites, but their site traffic is low, so I don't see myself really getting much success there. (odeen, writeroo, theprose.com, sweek, etc etc.)
Webnovel has a large reader base, but I don't like the terms and conditions or the terms of their contracts.
Tapas is the best for me, followed by Royalroad.