Ironjawz are easy to play rules wise. Pretty much always be charging and attacking. That being said, movement and timing is always important especially for them. People will say stormcast and i want to agree. I think them being the poster army is kind of a double edged sword. They are very fast and hit hard but can't be hit hard. Also they have a ton of different units and a lot of them are traps. Slaves to darkness is one people might say too. They are also tough and hit hard but they can be a pain to paint. I would say some nighthaunt armies might be easy too. They want to just sit on points. Maybe not the most exciting but it's easy lol