What headphones would you recommend for gaming?

I'm very new and want to get some decent headphones mostly for gaming. I was thinking of getting opened back because I game in my room alone so that's not an issue. I was looking at the DT 990 Pros but, I don't know anything really. Also, should I get an amp or is that only for guitars I'm a little confused about what exactly they do. My budget is preferably under 200 dollars but I'm a little flexible on the price. I live in the USA. I am also interested in IEMS if there are any recommendations but I'd rather go with over-ear headphones.