Hi SoumyaHD,
I don't think you should just completely write off the Core i3 chips - they are extremely capable processors. From what you have been writing so far, and from the question about the HD4000, it seems that you want to buy a top-end processor which leaves no money for a decent graphics card.
For day to day office use, you will see very little difference in performance between an i5 3570k and an i3 3220. When it comes to gaming, the 3570k is a better chip than the 3220. However, if you stick an i5 3570k with a low-end graphics card you are still going to struggle in games and because of the bottleneck, the i5 3570k won't be used to its full potential anyway.
You need to aim for a well-balanced system to give you the best performance. I recommend going for the i3 3220 and an ATI HD 7850.
Here is an example from personal experience: I used to play BF3 on Ultra with an i3 2100 and an ATi HD 6950. (The i3 3220 is better than the 2100 and the 7850 beats the 6950). When I upgraded to a Core i5 3570k, there was an increase in performance, but nothing huge.