I think you can learn a lot about a person based on what they read or watch. With that in mind, I hope to share what interests me.
My pet hates: I dislike it when an amazing plotline is interupted by women who throw things at/and punch men for a situation that happened through no fault of their own – more specfically when it's the female's own fault. Unfortunately, the woman who turns abusive when she doesn't get what she wants, or just blames the male protaganist for all her problems, is a growing trend. Equally, I would prefer to read/watch something that doesn't keep highlighting the pervy hero's thoughts and his need to lift up skirts. Of course, the bigger the bossom of those around him, the more time is dedicated to close-ups and shots of him drooling or red-faced...
I avoid harem and magical girls like the plague (the latter often coincides with the type of anime my sister watches/reads, so I tend to watch/read whatever it is she recommends). And strangely enough coming from a female, I mostly dislike anything that has a leading female character. It just doesn't work for me.
The genres I tend to gravitate to: sci-fi, anything space-related or with guns blazing, massive robots, fantasy and action scenes galore, as well as detective series. I do love a good sports anime/manga too! More often than not, my preferences lean towards the darker kind.
Don't get me wrong, there are some fabulous school-centred girly-girly romances, and intriguingly real slice-of-life's, but they are by no means my staple diet.
And I need depth galore, wanting to know exactly what makes characters tick.
Most of all, I love giving manga/anime a chance as I realise it often takes more than five episodes/chapters to build up a solid plot or character story line. So I never drop something I begin – no matter how bad it is.