What are your preferences? Intel or AMD? I just built an Intel build for about $750. If you wish to go Intel then I'd go for-
Intel i5 3330 @ 3.00Ghz
Gigabyte H61M-S1 Motherboard
Kingston 8GB RAM (2x4GB)
Nvidia GTX660 2GB (Non TI)
Cooler Master 600W Thunder PSU
Samsung 22" LED Monitor
Microsoft 200 Wired Keyboard and Mouse Combo
If you're an AMD/ATI guy, you're looking at something like an FX8120 or an FX8350. For the motherboard, look at something like the Gigabyte GA 970A UD3 or the ASUS M5A78L-M LX V2 Motherboard. If you want a detailed list of all the motherboards which have your desired socket, look at
http://www.flipkart.com/computers/computer-components/motherboards/pr?p%5B%5D=sort%3Drelevance&sid=6bo%2Cg0i%2Cy7i&q=motherboard (Prices will be in INR, you can easily convert them) or use something like Newegg or the PC Parts Picker. If you want an ATI/AMD graphics card, look at the Radeon HD7870. Don't focus too much on cooling as this is an entry level build. Also, you don't really need an expensive case.