Depends on what your primary use for the computer will be. For gaming, I'd say i5 CPU (unless you can get an i7) with a good clock speed (probably at least 3GHz; around 4GHz, even better). Not a motherboard expert, but I have a Gigabyte X79- something, and it works great. I've had an Asus motherboard that was good too. Where my current one is a X79, I think Z87 is newer (?). I'd go with at least 8GB of RAM (2x4GB). On the graphics card, it just depends on if you want to spend less now, and have to upgrade sooner, or spend a little more now, and not worry about having to upgrade soon. NVIDIA GeForce GTX cards are good, and the model numbers tell you info about the card. The first 2 numbers are what you should look at mainly...(Ex.) GTX 670 = (6)- Generation/how long ago the card was made (GTX 900 series just came out, so the GTX 670 would be 3 generations old (not a huge deal). The second number is most important. It indicates the power/capability of the card. So, that GTX 670 above would be pretty good (with the 7 in the middle). I'm using a GTX 780 right now, but I have another computer that has a GTX 555, and it still runs everything (although I can't max the graphics settings out like I can with the GTX 780). The power supply depends on what you get in the other categories you listed... i5 CPU, GTX 670 (example again), and 8 GB RAM, a 600W-700W power supply should be more than enough. Hope that helps some.