I'm really just a reader of fanfiction and only have this account for leaving the occasional review; although, I do keep favorites below for anyone who's interested in having stories recommended to them. While I do like a good AU story now and again, I mostly prefer stories that stick to canon characterization and pairings. This usually leaves me with canon-compliant stories and AU's of the "What if" variety (and a couple of guilty pleasure categories, like Soul Bonds). A story with outlandish pairings or where the "good guys" go dark has to be very well-written to catch my interest.
In other words, I loved all of canon -- all 7 books! -- and I prefer stories that stick to the spirit, if not the details, of what JKR wrote. While some authors are talented enough to overcome this flaw, I do not like it when people are "anti" a character that JKR clearly meant us to like (i.e. Dumbledore, Molly, Ron, etc.). I think that it is one of the main points of canon that even good people are not perfect (yes, even Harry!), and that forgiving each other for our faults is part of the Love that is the strongest magic. Save the "bashing" for Tom and his cronies! (NOTE: This is especially true of generalized "Weasley-bashing." How we ever got the idea that a close and loving family was a bad thing I'll never know. Love and "doing what is right and not what is easy" includes putting up with difficult, annoying, and sometimes even controlling family members.)
Also, by "canon" I mean the 7 books only (well, perhaps Beedle, Fantastic Beasts, Quidditch Through the Ages, and the flying motorcycle prequel could count as well) and NOT any extraneous comments by JKR. I find her statements interesting, but they are not as well thought out as the books; therefore, I think fanfiction authors are under no obligation to take them into account in order to earn their "canon" badge!