If your thinking of buying a premade PC than Acer, Dell, HP, and Lenovo are alright. If you plan to build your own PC (which you can save a lot of money than buying a premade one than pick your parts here
https://pcpartpicker.com/).. ***If you have no experience or too afraid that you build your computer wrong than ignore that link.
What you should be looking for in a PC is CPU, RAM, and (maybe GPU if you play games).
CPU - Never Dual-core, Pentiums, and i3 processors. i5 processors or higher is good (Intel). AMD chips aren't good unless it's overclocked or your building a budget PC. Most premade from Comp brands use Intel
RAM - At least 4gb or more.. Never higher than 12gb ram (that is too much), and you can add in more ram if you need it
GPU - If you are not playing any games that uses modern graphics, than Intel HD graphic is more than enough for your comp (is standard for home users). If you are thinking of playing games on PC, than you need a higher end GPU. Integrated GPU will not be able to handle current games (or graphic heavy game), only discrete graphics can... Radeon r9 270 or Geforce 760 is comparable to the next gen console ps4 and xbox 1
CPU and GPU is probably the most expensive part in your computer
If you are looking for pre-made gaming PC than Cyberpower and Ibuypower are pretty decent.
**Just BEWARE that if you buy premade computer, you might have DOA (which is dead on arrival). Rarely happens but it can happen.. Also pre-made computers have Windows 8.1. If you don't like Windows 8.1 or don't have ur preferred windows OS copy, than you should wait for a month or two until Windows 10 comes out.