I purchased this one 2 years ago and would buy it again and again.. love it!

Sleep Innovations 4-inch Dual Layer Gel Memory Foam Mattress Topper Enhanced Support, Queen https://smile.amazon.com/dp/B00CEMH3C0/ref=cm_sw_r_cp_api_glt_fabc_MQVMW0CAYPY10KYCDVX5

I have had this since 2019, it has been and still is amazing. Just firm enough and doesn't sink.

Sleep Innovations Dual Layer 4 Inch Memory Foam Mattress Topper, Queen Size, Medium Support, 2 Inch Cooling Gel Memory Foam Plus 2 Inch Pillow Top Cover