New
#11
For what purpose?
You may be disappointed with any processor upgrade. There are better ones than a core I5, but for most purposes it may not be obvious.
Using an SSD for the boot drive may make things feel zippier.
If you want to play high-end games, get a better graphics card. That'd be the most significant upgrade.
If your main goal is bragging rights, get a system with a Socket 2011 I7-3960X CPU, Asus Rampage IV Extreme motherboard, 8X8 GB DDR3-2400 RAM, dual 512GB SSDs in RAID 0, three or four Radeon HD 7970 graphics cards for Crossfire, etc. Water cooling, but of course. You can climb to the top of the hardware heap - for about three months.