Everyone will have a different answer, and it all depends on your budget, you can spend 1,000 or 20,000 baht on a graphics card alone!
But if you want something to last the next five years I'd go for the following ...
CPU: Intel i5 or AMD FX 9000 series
RAM: Kingston DDR4 16 GB
Hard Drive: SSD 256GB (keep your data on a portable hard drive)
Graphics: Nvidia GTX 1050 or Radeon R9 285
PSU: Coolermaster or Thermaltake 700 watts or above
Of course your mainboard will depend on which combination of the above you go for, if you have deep pockets go for the i7 CPU. The solid state drive will be a lot faster than a regular hard disk and you'll get a noticeable performance boost out of it - your data should be kept off the system drive. With graphics cards the sky is the limit, the two I've listed are both very capable but you can spend thousands on them. Most people over look the power supply and use a cheapo one that comes with the case and cannot produce the juice for the top end hardware. You should spend at least 3,000 baht on a decent PSU.
All of the components can be ordered online if you have the inclination to build it yourself!
is a great website for comparing PC hardware.