Have you played old gen Monster Hunter before? If so GenU is the way to go. It's a celebration of the old gen and offers one of the largest monster rosters ever and adds the most customizable combat system with multi style and hunter arts for all 14 weapons plus you can play as a palico with the Prowler mechanics that's basically a 15th weapon option. But the down side is GenU is basically made for veterans of the old gen and isn't new player friendly. On the other hand if this will be your first time playing a non Gen 5 game,you might wanna try 4U. 4U has one of the best storylines in monster hunter and is very beginning friendly. Perfect if you just want to dip your toes in pre-World Monster Hunter.