I recommend Anna Dressed in Blood. 
 ***** 
 SCARY. 
 Anna Dressed in Blood could've been a 5, if not for the romance that felt forced and nonsense. Blake has great moves in terrifying readers; i held my breath more than once on separate occasions! Thrilling and maniacal, Anna Dressed in Blood is one of the most frightening YA books i've read so far. 
 Cas started out as strong in character, but when Anna came along, he appeared scatterbrained and incapable. Are guys really like that? Hmmm. LOL. Anyway, Cas is just an average male lead for me. He could've been great, but his character's development became null in the end. Anna was so kick-ass on the first scene! Cold, ruthless, merciless. Then Cas started hanging out at her house, and there Anna began to show some emotions or what was left of it. She's okay, i mean i loved her when she's the "Queen of Death", but the solidity of her character when she's not the "Queen of Death" did not hold much for me. Perhaps i just want her to be at her baddest? 
 The horror aspect is fantastic. Voodoo magic has that air of mystery and fright that i don't wanna dwell in the middle of the night. The romance part is negligible. Lemme just say that a relationship between a human and a ghost is just uncomprehensible to me. 
 Anna Dressed in Blood is a good halloween read. If you're up for some jolly 'ol scare, this book won't disappoint. Well, just don't mind the romance and you'll be good.