Mouse pads are one of those accessories that not only can provide necessary functional usage, but that also can show off some serious flair. Nearly every PC gamer users (or should use) a mouse pad or mat of some sort: they help improve the life of your mouse, improve sensor feedback and increase your pointing speed and accuracy. Mouse pads and mats come in all different sizes with different textures and materials, so be sure to keep that in mind and do your research when shopping.
For the “elite” PC gamer who prefers function over looks, gaming mats like the Razer Firefly Chroma pad or the SteelSeries QcK pad are pretty solid options. Both companies as well as Corsair, Kingston, and ROCCAT offer a wide range of mouse pads in all different shapes, colors, and materials, with the majority of them being less than $50. Nothing is better than having a slick, matching gamepad for your gaming mouse.
There are also a number of gaming themed mouse pads that offer a little more pizzazz than your typical black pad. Blizzard sells an exquisite Hearthstone-themed pad that makes my eyes water with joy. There are a number of sites like Zazzle and Etsy that feature many gaming themed mouse pads, as well as a bunch of sites that let you custom create your own mouse pad.