The carbon fibers are really nice. There are also some specialized mats made for DJ's that are phenomenal and sound great. There is a cork mat too that one of my friends uses that is one of the best sounding in my opinion. Very expensive for what it is though.I've used felt, leather, and cork so far and the cork mat is far and away the best sounding to me. I've not tried CF yet but I'll keep an eye out!
I was using the Ortofon 2M Red but it got damaged and I've been using the At95e cartridge that came with my LP-120. I need to replace it but I keep buying albums instead. haha!
https://www.turntablelab.com/collections/record-mats-accessories-alpha/products/music-hall-cork-record-mat
This one is really nice too as far as anti-static technology and overall sound. https://www.turntablelab.com/collections/record-mats-accessories-alpha/products/am-clean-sound-anti-static-record-mat