Heather Graham always satisfies my need for a good ghostly romance. Her Krewe of Hunters series follows a group of gifted FBI agents as they investigate real crimes with paranormal elements. They aren't too deep so they are great for a beach or weekend read.
Haunted Destiny is one of my favorites and I have read A LOT of Heather Graham books. I love the setting of the cruise ship where a serial killer is said to be hiding. The two main characters are the piano bar pianist/singer on the cruise ship and the FBI agent who boards the ship looking for the killer. We meet ship ghosts murdered long ago, sail through a storm where all communication is lost, and follow a list of suspects who could all potentially be the killer. The characters were all likable and I always have fun trying to guess who the killer really is.