It depends on your habits as well as your budget. If you're kinda into gaming and your budget does not allow you to buy a capable laptop, then it leaves you only one choice.
If you do have the budget to buy a reasonable laptop, I'd go with that since you'll cherish the portability of it.
Note: Pure and badass performance can only be found in desktops. Laptops are getting stronger these last years and are quite capable of playing games at medium settings, but for great gaming performance, the price/performance of the wanted laptop will be close to zero.