which brand of cpu is the best?

The latest Intel Core-I3 would be great for you. It is low in power consumption. It has an internal graphics processing unit (GPU) that allows you to play games and watch movies at good quality even without buying a separate video card.

maybe you are referring about branded models of computers such as Dell, Acer, Compaq and others. Usually you can check out on their website to see which one fits your needs. Each brand has its own unique features compared to others so you must be selective so that you can have the one that fits your budget. If you are planning to buy a second hand unit, you must take note that you cannot be sure of its condition because it depends on the first owner of the computer on how he/she uses it. If you are really on a tight budget, you may ask someone you know who has knowledge on computers to help you find the correct parts with your current budget. This way you can have a computer that is of good quality with great performance and good upgrade options in the future.

Now in present time Intel i7 cpu are available in market.. so time by time technology may have changed.. so you can't say which is perfect.. but in that time i7 cpu is the best...

I think that intel has the best quality of cpu's. Its new series is really great but since you have a low budget, you can consider intel's dual core one. The new one comes for around 6000-8000 and if you take a used one it depends upon the time and volume of its usage. But still the it may cost you around 2500 or lesser. It also depends upon the area from where you are buying as you get it cheaper in lemington road in mumbai. I stay in mumbai so I can only tell you about good areas in and around mumbai.