Currently, I tend to read similar genres. I span out when something piques my interest, but I guess it all began with fiction. As a kid, my favorite book was the Velveteen Rabbit, one I made my mother read to me a zillion times. So, I read children's books (as children do), and when I reached the ages of 8 and 10 and such, I would do the occasional book report.
Of course, I never liked the books available to me. I used to get out of the book reports by not participating, and as a "punishment", I would sit in the hall and have to write a story and read it to the class. I guess I though the world of books was limited. The only thing that I used to read were Fat Cat, Garfield, and other "humor" books. Until...
I read that book so many times, that the spine wore out. I still have it on my shelf, even though many pages are no longer attached, because it's a bit of a memento of where my love for reading began. Thus began my love affair with Stephen King, and I consumed everything he wrote.
One story that stands out in this book was "The Boogeyman". After that, I didn't sleep with my closet door open - just a crack.
We didn't have the internet back then to Google books, and none of my friends read.
Hands down, my favorite story is "The Masque of Red Death".
Then began my love affair with poetry. I'd say I wrote poetry and short stories on my own off and on throughout childhood since it started with those pesky required assignments in 3rd grade. But when I found poetry, it's all I wanted to do. I got my drivers license and would spend HOURS at the library discovering new poets. I had a friend in school where we passed a notebook back and forth and would write poems in them, or song lyrics, because around that time I thought I was going to be a famous rockstar.
Then I picked up popular best sellers, mostly staying with the fiction and autobiography genre. I love hearing about people's first books, it's so interesting to see what stories really turned us on to reading where it became more than a book report. I always loved vampires, but the urban fantasy genre back then just wasn't where it's at now. I don't recall many books, if any, with strong female leads and supernatural characters. I never read romance either, because most of those books where about strapping pirates and their damsels in distress. At least, that's what it looked like from the Fabio covers. I continued to read Anne Rice, and I believe one of my first UF books was the Sookie Stackhouse series.
My brother and I still exchange humor books every so often; we have a really disturbed sense of humor and are always on the lookout for something especially bizarre. (like "This Book will Change Your Life"). Right now, my heart is firmly planted in UF and PNR. I still love other genres, and some of my favorite writers, but this is where I feel the most escapism, and possibility from a creative standpoint.
What are some of your first adult books that really got you into reading? It's hard to forget them...