Big Harry Potter fan,
preferences go to stories of length, prefereabl over 100k words so it keeps me busy for a bit - but short ones will do just as well.
I prefer Dark / Intelligent Harry fics, where he just acts more logical and smart, or where he comes into his heritage at some point early.
Favorite characters include Harry, Sirius, Nymphadora Tonks [or Black if she goes back to her roots so to speak] , Luna Lovegood, Daphne Greengrass, Tracey Davis, Blaise Zabini [either boy or girl version] Any Dark/Darker than usual version of Hermione, Neville, Luna and Harry. And off course i cannot help but love a sane/semi-sane Bellatrix, or one that somehow picks Harry's side or trains him or w/e.
Least liked characters:
Ron, Ginny and Molly Weasley, Assuming canon or mostly canon.
Canon Dumbledore, Snape and Draco + Lucius Malfoy.
Narcissa, i'm not sure about - she's just looking out for her family mostly.