Essential PC Upgrades for gaming
There are a few essentials that every PC gamer needs to be at their best, and playing with a team without these essentials can be quite annoying at times when you can see or hear something your team mate cant, and you lose because of it.
Any size monitor will do, but for a huge advantage get a widescreen, 16:10 preferably. This gives you about an extra inch (1680x1050) on either side of your screen that regular 4:3 monitors don't show. This is big, it could mean the difference between winning and losing, dying and living because you can see so much more.
Again, sound is extremely important, you need a good headset (and headsets only unless you want to induce echoing through voice comms) and soundcard if you want to do well. A good headset means you can identify exactly where the enemy is. Just for a example, on italy once I knew exactly where someone was because he was reloading; he was around two corners from me and up to the right around the second (and it wasn't exactly a place where you would be up and to the right, so no guesswork there). I got called a wallhacker. A soundcard is also needed to give clearer, crisp sounds and to increase overall system performance by taking the sound calculations off the processor. I currently have this soundcard with this headset which comes to about £55 (you can probably get them at about the same in the US), and they work great together. I get crisp, clear and surround sounds in a headset.
You need a good mouse, but mainly you need to be comfortable with it. I've gone through two Razer mice and am currently using the Logitech G9 and at the moment it's great. It's really comfortable and customizable, its even got weights you can use to change the weight of the mouse. As I said, as long as your are comfortable with it you should be fine. My main point for mice is that you need a mousemat. A good sturdy one at that. I would recommend the Razer eXactMat, it's made from metal so it doesn't bend and has a rough side (control) and a smooth side (speed). A mouse mat will make your aim better because you have much more control because of the flat, even surface designed for mice.