Please help us help you better. If someone answers your question without asking for more information to actually help you get what you really want...then you already know that they are just throwing out cookie cutter and quick answers. I want to actually help you as much as possible which is why I ask these questions.
If you have already provided some of this information, and see the question below, that is merely to clarify what your posting already stated.
1. Do you need a keyboard? Any preferences? Wired/wireless/mechanical?
2. Do you need a mouse? Any preferences? Wired/wireless/DPI?
3. Do you need a monitor? If you already have a monitor/tv, what type is it and how many hz is it? Do you plan on using multiple monitors? Or do you have any monitor/tv preferences? Screen size, built in speakers, resolution, refresh, hz?
4. Do you want a blu-ray drive, dvd/cd drive, or no drive? If you already have one, what is it?
5. Do you prefer Intel or AMD processors? If you already have a processor, what is it?
6. Do you want to be able to overclock the processor?
7. Do you prefer NVidia or AMD graphics cards? Do you plan on using multiple GPUs at a later date?
8. Do you plan on overclocking the graphics card?
9. Do you want to have more options for upgrading later on, such as adding extra RAM or running multiple graphics cards together?
10. What operating system do you prefer, Windows 7 or 8.1, or Ubuntu/Linux? If you already have an operating system, then what is it specifically? For example: Windows 7 Home Premium 64 bit. (list the entire specifications for your operating system. Check this link if deciding what Windows OS you want
http://msdn.microsoft.com/en-us/library/windows/desktop/aa366778(v=vs.85).aspx )
11. Does your budget include the operating system?
12. Do you prefer air cooling or liquid cooling?
13. Is there a particular case size you would like to go for, mid tower, full tower, etc?
14. Is there a particular theme or color scheme that you prefer, or a particular style case? (Please give a few examples)
15. What is your budget, minimum and maximum costs?
16. What sort of games or programs do you want to use? (Please give plenty of examples)
17. What settings, fps, resolution do you want to play those games at?
18. What country do you live in, so we can know what currency and/or sites to link for you?
19. Do you have a hard drive type preference, such as normal hard drive, hybrid, or SSD? Or do you want a smaller SSD for the operating system and a normal hard drive for saving files to?
20. Is there any other component that you already have that was not asked about specifically already? If so, what is it?