Any pleistocene megafauna. Obviously mammoths and elasmotherium would be incredible hunts, and Irish Elk (Megaloceros) would be the best for trophy hunters that wanna display a big rack.
Me, though, I'd want to hunt the carnivores. Homotherium and Cave Bears.
>>1588513velociraptor mongoleinsis was three feet tall, look up dakotaraptor, utahraptor, or deinonychus, any of those would absolutely destroy a human being and be a nightmare to deal with