1- Cheaper games:

Upset with paying $60 for a new game? PC games get discounted much faster than their console counterparts, so savvy shoppers can often pick them up for a fraction of their original prices just a couple months after release

2 - Better Controls:

Gamepad has its place. But can you imagine playing The Sims 3 or Starcraft 2 on your TV, with no mouse or keyboard? It’s not a pretty thought — and games with complex interfaces are always going to flow better on the PC.

3 – Play the Classics:

Sure, it’s the new games that get all the headlines, but the PC has a back catalog that spans decades, and there’s no platform that does backwards compatibility better.

4 – MMOG

Despite the noble efforts of a few developers, online virtual worlds remain a PC-only affair. Whether you’re into classics like World of Warcraft or new hotness like Star Trek Online, the PC’s the only place to be, and there’s no sign of that changing any time soon.

5 – 3D

Console games are taking their first tentative steps into stereoscopic 3D, but on the PC it’s already a fully-fledged reality. Modular and infinitely upgradeable, the PC’s architecture makes it easy

6 – Overclocking

In many cases, purchase a lower performance CPU or Video Card, cheaper component and overclock it to the clock rate of a more expensive component.