Choosing a Laptop for Photoshop Use
I am not aware of any one laptop that particularly stands out, although I certainly have come across a few to avoid. The first thing to say is - unless you really need a laptop, go for a desktop instead - see here for notes on that.
If you're a Mac user, the choice is obvious - a Macbook Pro. Be aware
the screens on Macbooks are not really that great from a colour point of view, even
the 'Retina' ones are just mediocre. In general, with Mac laprops, the price to performance ratio is
often not as good as in the PC world, but the hardware is very nice in
all - it's just a shame about those screens. The Macbook Air is ok for only light work but they do tend to struggle on bigger files/libraries. Oddly
the Macbook Air screens tend to be better than the non Retina Macbook
Pros, but still pretty low end from a colour point of view.
My personal preference on the PC side is for Asus laptops, for an
imaging & general quality point of view. Lenovo Thinkpads are very
good too, and HP have nice options in their upmarket Envy/Creative lines.
Look for a model with the best screen option - ideally the
panel is IPS or at least SPVA (definitely NOT a TN panel).
The laptop should definitely run off an SSD, and have an i5 or i7 processor. Windows 10 64 bit is the obvious choice, and 3D graphics acceleration
makes Photoshop a LOT nicer to use, so it's worth looking for a decent
video chipset as well. Of course, get as much ram as you can afford.
The best reviews are probably found on Notebook Check. If you scroll down in their notebook reviews, you will see gamut plots against sRGB and AdobeRGB, discussion about uniformity and viewing angles etc.
Those are the key things. Obviously a custom desktop would be the best
option form a sheer power/price perspective, but laptops these days are
really pretty effective as well.