HiFi - For The Audio Connoisseur

Looking for headphones for use at my computer. Primarily for gaming but also music. Lots of people online recommend the Sennheiser HD 560s but I figured I'd ask to see if there's anything else worth looking at. I think I want open backs since I'll primarily use them at my desk by myself.

My criteria are: -Decent price (around $200 or less) -Option for microphone attachment (also looking for recommendations there)

If I were to go with the HD560s, would I need an amp to take full advantage of them? If so, I would also like recommendations for that too, as I don't really know anything about them. Any other advice you could give me would be very beneficial. I'm new to the audiophile scene and don't have a ton to spend on the best of the best in gear. Thanks!