Josheir said:
I want to buy a computer for developing C++, Java, PHP, JavaScript, jQuery, SFML, and 3D (So far OpenGL and LWJGL), etc. I have a budget of one thousand dollars for a tower, and although I don't need to spend this much, I would love a nice experience.
All of these can be done on any machine from the last decade, many can run just fine on machines that are even older.
In the business world it makes a lot of sense to get high quality products; when you're paying developers many thousand dollars per month you don't nickle-and-dime their equipment. Whatever you “save” in what equates to a few days wages on cheaper computer parts is more than offset in exchange for a drop their performance by 5% for 2-3 years until the next hardware upgrade cycle, those businesses are costing themselves a fortune in reduced productivity.
For personal use whatever you've got is generally good enough. You as an individual likely won't be putting out cutting-edge products that require the absolute latest and greatest cutting edge equipment. You as an individual won't be looking at multi-hour resource cook times. You as an individual won't be looking at hour-long compilation times, or hundred-gigabyte builds, or other things that slow down professional programming.
If the machine is capable of playing high end games, it's more than enough for personal programming projects. Whatever class of computer you're planning on getting, look at the caliber of games that can be played. That's exactly the quality of graphics, game performance, etc., which the hardware can handle.