I built my computer almost two years ago, and it's probably due for an upgrade. I don't think I really want to build a whole new computer, but I might be interested in upgrading parts of it. What would be a worthwhile upgrade for me? I don't really have a specific budget, but less would obviously be better.
Here are my current specs:
RAM: 8 GB of G.SKILL Ripjaws Series DDR3 1333
Motherboard: ASUS M4A79XTD EVO
CPU: AMD Phenom II X4 955 Black Edition
Power Supply: Antec EarthWatts EA650 650W
GPU: HIS H489FN1GH Radeon HD 4890 1GB
Case: Antec Three Hundred Illusion
SSD: OCZ Agility 3 120 GB
HDD: Western Digital Caviar Black 640 GB
Getting a 1080p monitor would be my first upgrade for that setup. Other than that, you're set for now.
Depending on what you do, you could either OC the CPU if you're not much into gaming or upgrade the GPU if you want to play more recent games that are graphics intense. Outlander's suggestion of choices for graphics card is good when you feel that the games you're playing have outgrown your GPU.