Ultimately, if your budget is around $1000 and you don't want to go too overboard then yes, for what the specs are in the Lenovo Y50s they are good gaming laptops.
They will have the real i7 quads instead of the dual cores, they'll mostly come with 8 GB of RAM, and the standard video card on them will be the GTX 860M which for a laptop won't be able to go ultra on newer games, but some older games you'll be able to get high easily.
If your budget was more, consider the ASUS G551 or G751, or even the MSI DOMINATOR. The ASUS ones for the most part will also come with similar specs but they'll have a better display, and the overall quality would be higher. The MSI DOMINATOR depending on the model will cost roughly $1500 and have the...