I think Michael Crichton writes brilliant Mainstream books that often have elements of spec fic (Timeline, Jurassic Park, Lost World) or fantasy (Eaters of the dead).
Timeline was a great read and a less than average movie, Jurassic Park was incredible at its release for special effects and the books are great reads that incorporate spec fic and elements of horror.
For those who can stomach gratuitous violence and the perverse, I think Clive Barker does Fantasy/Horror superbly.
Stephen King I believe, has transcended the Horror genre and is simply a brilliant writer, whether it's Dark Tower for fantasy, Fried Green Tomatoes for mainstream or good old fashioned Horror such as, well... The list is endless.
Oops sorry FB, I mis-read your post, you want transcending genres rather than blending them!!!!
Um...
I like Matthew Reilly, he writes incredibly paced action/adventures like TEMPLE and ICE STATION... But there is nothing deep or earth shattering to them. I also thought Perdido Street Station was pretty spectacular, but probably too fantasy-ish for most.
Ooh I know!!!
Billy... Written by Pamela Stephenson was amazing.
