The Best Affordable Sound Card?

So, I listen to a lot of music on my PC and have a pretty decent set of headphones Audio Technica ATM-M50. As well as doing a lot of gaming on my computer I'm kinda interested if a sound card would really improve my experience. I haven't had one in a PC of mine for about 5 yrs I know they used to make a good difference and helped system performance a lot. But with the little research I have done seems to point to the onboard audio being really good nowadays. My question is here if I were to spend around a 100 dollars or a little more would it be a noticeable upgrade in terms of sound?