The CPU and the motherboard have to be compatible with each other by socket, and typically each CPU type has a different number of pins. So in choosing one you limit your option for the other.
One of the best ways to pick a CPU is to know your work load. Newer generations of CPU have more and more instruction sets, however if you don't use them they go to waste. The other major choice is speed plain and simple more Ghz or more cores depending on your work load.
recommend a CPU that is as adaptable as possible to the user?
The only way to be as adaptable as possible is to have a CPU will the most instruction sets. However, it comes at an increased cost.
The selection of the motherboard is primarily based on what the user needs. For example:
If you need 10 USB 3.0 port you have eliminated a bunch of options
Similarly, if you need 6 pcie 3.0 x16 slots you only have a small selection of boards to choose from.
Need a M.2 slot even fewer motherboard to choose from, need 2 or 3 m.2 and now you only have a few choices.
Need USB 3.1 type 2 for 100w of power, not many choices currently exist.
Have multiple of said requirements and your pretty much down to 1 or 2 choices.
Coming back to adaptability. You can pretty much code any program on any modern CPU, but one CPU may have hardware support for a specific task, and therefore run faster than the CPU that has to emulate an instruction in software. So adaptability isn't really a problem its just a matter of how efficient/fast it is. You may have to write the code differently for different CPUs to maximize the efficient/speed, but you can still write code to have the same end result for the user for almost any CPU.
If you meant video cards and not video plates, again its about feature set. For example, tessellation is consider too slow to be done without hardware acceleration. The newer video card could have tessellation in the image, and the older one won't. Gamers want 60fps(frames per second) some time 30fps can be dealt with if the game is amazing enough. So even if tessellation could be done with software it would drop the frame too low. Therefore tessellation is only on when hardware acceleration is available. There are dozen more features like this.
Memory, for people who care, it comes down to speed. How many MB/s or GB/s can I get from a certain configuration of memory. All the settings are surrounding RAM are delays. It take # of clock cycles to set the row, and # more for the column, and dozens of additional settings. Anything that can be done to reduce the total delay increases the overall speed.