There's an older game called Spartan Total Warrior on XBOX and PS2, it's you up against massive amounts of enemies at once, cleaving through them like butter.
For a more modern game, I would suggest Middle Earth: Shadow of Mordor. If you have the right player skill and have invested in the right runes you can walk into an enemy stronghold of orcs bold as you please and proceed to massacre them en masse with little regard to self preservation. There's no worry of parties, inventory management, or tactics, it's all about killing the way you want to, and Shadow of Mordor gives you A LOT of freedom in how you kill. You have a sword, dagger, and bow, but they are more than enough to experience the game however you like. Definitely check it out.
For a more robust RPG experience, try Kingdoms of Amalur: The Reckoning. While in many ways it might seem a bit lackluster compared to other open world RPGs, combat is where it shines. Every style of combat feels great, and each fight often ends with a feeling of "awww, but I wanted more things to kill" as you are just having so much fun. I would highly recommend it for the combat alone, it's just a joy to play.
Mount & Blade Warband does indeed have fabulous combat but it falls flat out of context. There's no overarching plot to drive you forward, no real preset goal, and this works fabulous for a sandbox open world RPG that lets you do anything but not so good if you just want to dive into a hack n' slash marathon against enemies. Plus you WILL start out weak and puny even if you invest all your points into combat related skills, you won't stand much chance of going solo in battle, and you need to recruit an army to survive out there, most enemies you encounter are in large groups and they only get larger as the game progresses. I would not recommend this game solely for someone who wants to just go on a wild solo "me vs. the world" campaign, at least not if you don't like Dark Souls level of difficulty
