One thing that I'm asked from time to time when people are looking to purchase something is what piece of technology/equipment is "best.
Unfortunately the answer for that is not always clear.
Sometimes there are cases where a specific piece of hardware is built much better than another, however even in a case where there is a huge difference in the quality of one device over another that would not make the more expensive product the best one for the person who's using it.
Cameras are a good example of this. Regardless of how good the technology is a camera phone is always going to have shortcomings that a DSLR or other camera with a larger sensor and better quality lens would be able to overcome. However, most people are not wanting to be running around with a massive digital camera in their bag everywhere they go. As far as cameras go the best camera is the one that you have in your hand and will actually use.
That makes the cellphone cameras that most people are running around with in their pocket the best camera out there since it's the one that they will actually use.
As far as computers go you should be looking at what you need the computer to do and how you are going to be using it before you make a decision on what you are going to purchase. In a lot of cases the software that you need to run is going to dictate a lot about what you are looking to purchase. If your software requires CUDA cores or some other hardware specific piece of technology purchasing a computer without that requirement is going to ensure that you have a bad time.
The biggest constraint that a lot of us are going to run into is our budget. Not everybody has an unlimited budget, if we did this entire post would be moot as you would just go out and pick up the fastest of everything that was available. This is however the real world and not all of us have 10k to drop on a system.
The other thing that I would get most people to think about is if you need to be looking at a laptop, or if you are looking at a desktop system.
While I personally prefer a desktop system for my personal device work almost requires that I have a laptop to work from since I need to be mobile fairly often. For personal stuff that's not as much of a concern. Sticking with a desktop system is generally going to be a better value for performance and far easier to repair in the event that something goes wrong with the device.
Afterall, if you break the display in some laptops you may as well go get a new one for what it's going to cost to replace the laptop display. My desktop display goes wrong I just go pick something up from the store to replace it, possibly something better than what was in place.
At the end of the day the decision about what hardware is best is going to boil down to your satisfaction with the device you wind up with. Everybody is going to have their own opinion but as long as you are happy with whatever device you wind up working on, and you fell that the price you paid was fair that's all that matters in the end doesn't it?