I'll be posting a few of these over the next while, but I recently had to upgrade my video card for what may be a silly reason -- I had friends recommend the Witcher books and games to me, so I was able to play through the first one no problem with my onboard card. The game is pretty ancient now. I had to put the second one on super-low settings in order to play it. Witcher 3 on the minimal settings in full screen was Geralt [main character of game] moving around like he was underwater and in slow motion. So, much like when the Lord of the Rings Director's Cut DVD boxed set came out and I decided that was the time to buy a DVD Player finally, it was time to upgrade the video card. After discussing with the same friends who recommended Witcher to me, I went with a GIGABYTE NVIDIA GeForce GTX 960. There were budget issues and impatience issues.
Some told me to wait for the new AMD-based card, because it would be a nice price and supposedly much better, but after having fried almost every AMD anything I've ever had, I decided to go with NVIDIA. Below are a couple of screenshot crops from Diablo III. Keep in mind that I had to play D3 on the onboard card with low settings and frequently in windowed mode to avoid certain rendering issues with the onboard. I now play it on the highest settings and in full screen without issue.
There are some major differences in clarity, if you're visually inclined, but the main thing is definitely the performance. It's nice to have the ability to play on higher settings, not worry too much about rendering issues, and well, everything is much prettier!
Will post some screenshots from some other games that I have old screenshots for and new ones, or I'll get industrious and enable the onboard to get some new ones for comparison. Interestingly enough, even ancient games like CivCity: Rome perform much better and look nicer, despite the fact that the onboard should have been able to handle them without issue.