Hi Holly!
One suggestion that I think you may like are the "Anita Blake" books by Laurell K. Hamilton. There are about 9 in the set - I think!
They would be great for "train-reading" fast paced, funny, gruesome in places, has a horror crime to solve and a strong female protagonist - Anita Blake.
She is a vampire executioner with an attitude (nothing like Buffy.)And an animator - brings the dead back to life so relatives contesting wills and so forth can find out what their poor dearly departed really wanted to happen with their estate.
Also she is brought in on preternatural murder cases by the police - that's the mystery part of the book.
As each book moves on you get to know her and her "friends" more. They include a Master Vampire, Jean Claude, a sexy werewolf, Richard, a cold blooded assassin, Edward and heaps more.
I love these books, Holly. Very addictive.
The first one is called "Guilty Pleasures."
deb