For the best laptop for you and if the kind of speed you are after is for PC gaming, the what you really need is a king of laptop with a very fast dedicated graphics chip, or GPU processor. Most of the current leading-edge gaming laptops in the market today comes with various flavors of Nvidia's GeForce mobile chips.
If your laptop has a 1080p (1,920-by-1,080-pixel) display screen, then a GeForce RTX 2060 or GTX 1650 chip processor will be usually a good match, that is if you play modern games at high settings. The other type, the RTX 2070 is generally sufficient for a resolution of 2,560 by 1,440 pixels (or 1080p, this is if you want to buy with an eye to the future), while a much costly GeForce RTX 2080 will be overkill for 1080p but a good starting point for gaming on a 4K (3,840-by-2,160-pixel) screen. That said, most gamers stick to 1080p.
If you'll use your gaming laptop with an external monitor or monitors that have a higher resolution than the laptop's built-in screen, you might consider a GPU that's several steps ahead of the laptop's own screen. Otherwise, you'll want to match the performance of the GPU with the upper limits of the laptop's own panel.
One wrinkle to all of this is the emergence of high-refresh displays in laptops. A typical 60Hz laptop display (which redraws the screen 60 times per second) won't show much benefit from frame rates in excess of 60 frames per second (fps). If your high-powered GPU can churn in a given game at a consistent 100fps, you won't see much added smoothness. However, some gaming laptops are starting to ship with high-refresh panels capable of rewriting at 120Hz or more. These screens can make use of those extra frames for smoother game play, and can justify a high-powered GPU paired with a 1080p screen.
On a related note, laptops with screens that support Nvidia's G-Sync technology are worth looking out for. In these, the screen rewrites at the same rate that the GPU churns out frames, in essence adjusting the refresh rate dynamically. This reduces screen artifacts and "tearing" (in which parts of the screen misalign for a beat as they are rendered). With a high-refresh screen, a top-notch GPU will be better leveraged; with G-Sync, a marginal one will be enhanced.
Another factor, if you're shopping for a maxed-out laptop, is virtual reality compatibility. You'll want to look for a model with a GeForce GTX 1660 Ti or higher GPU if you mean to run a virtual reality headset. It's best to opt for the right GPU now if you might want to explore VR later, as you can't upgrade the GPU after the fact.
We've mentioned one Nvidia technology, G-Sync. You may encounter another one called Max-Q, which slightly dials back the speed of a GeForce graphics chip in order to reduce its operating temperature, letting you get, say, a RTX 2070 in a thinner laptop with quieter cooling fans than would otherwise be possible. Still another Nvidia trademark is SLI, which stands for Scalable Link Interface and means two GPUs working in tandem; it's found in only a few ultra-high-end gaming laptops.
