If you are looking for the best integrated graphic core in a Core i5, then that would be the Intel HD 4000 in the Ivy Bridge series. While around 40% more powerful than the older Intel HD 3000, it is only around as powerful as a desktop Radeon HD 5550 graphic card. Good enough to play most games with a mix of low & medium quality graphics at 1366x768 resolution with decent performance. Unless of course the game has really demanding graphics like Metro 2033
For "high" settings you need to consider at least the nVidia GTX 660m, but it also depends on the resolution you want to play at. Just remember that the more performance you want, the more money you need to spend.
Lenovo sells the IdeaPAd Y580 which has a GTX 660m. See following link for models. There are only two different screen resolutions though, 1366x768 or 1920x1080, depending on which model you get. There is no 1600x900 and the GTX 660m is a bit weak for 1920x1080 since it is only considered an "upper-end medium" performance graphics card.