Help upgrading computer

[jfunchio]

So my current build is probably 4 or 5 years old now and I think it's time for an upgrade. I want it to be able to run games at the top settings while at the same time having multiple browser window open with video streaming. I'll probably eventually have a second monitor as well, not sure if that effects performance or not.

This is my current build:

Cooler Master HAF 912 - High Air Flow Mid Tower Computer Case $59.99
Power Supply: Antec EarthWatts EA-500D Green 500W $59.99
Motherboard: MSI P67A-G45 $132.99
Processor: Intel i3 2100 $124.99
CPU Cooler: CoolerMaster Hyper 212 $34.99
RAM: G.Skill Ripjaws 4GB $44.99
Hard Drive: Samsung Spinpoint F3 $64.99
Optical Disc Drive: Sony Optiarc SATA DVD/CD Burner $20.99
Graphics Card: SAPPHIRE 100314SR Radeon HD 6870 $209.99

I wanted to know what I can keep and what I should upgrade. My top priority is being able to run multiple programs at once smoothly, so I would think the CPU is the highest priority which means I will probably need a new motherboard. I know the graphics card is important for the games part, but for now a decent one will do leaving room for an improvement later. I will probably need to upgrade the RAM as well and probably the power supply.

I'm not very experienced with this so I kind of just wanted to get some advice or some ideas for upgrades. My budget is probably around $500-$1000, preferably on the lower end, but can spend towards the higher end if needed.

[Fascinate]

Your system is pretty good still man, what are you having problems with?

[Lathais]

What games do you play and what kind of performance are you currently getting? While I understand wanting to upgrade every few years, you should be ok in most games for a little while.