I remember this book from High School. It was not one of the classics, but would love to re-read it. Plot involved a game with humans (on earth) being hunted by a set of shapeshifting aliens (who paid to hunt the people). Think of it as a mashup of Robert Sheckley "10th Victim" meets "Predator." One of the "hunters' used an Uzi to kill its prey. May have had an element of reality gameshows.
If this is the book I'm thinking of it was part of a two book series. People thought they'd won some sort of contest but were double crossed and taken to be hunted by the aliens. One was an Idi Amin-style African strongman and his kind of wimpy son. OK, I found it. The book was either "The Hunters" or "The Treasure Hunters". Both books by Burt Wetanson and Thomas Hoobler. From Amazon (The Hunters)
"A mysterious couple arrives in a small Montana town and offers its residents a trip to Paradise. Instead...they get a taste of hell on earth."