I built my current computer about three years ago. I always buy at the price-break, so I can get the best quality at a reasonable price. I choose an Abit IC7-MAX3 motherboard. It's a socket 478 board that supports 800MHz FSB and Hyper Treading.
I purchased a 3.0GHz Intel Pentium 4 Northwood core processor and 1GB of DDR400. I used a graphics card from another computer to save on expenses. It's an Nvidia GeForce 4 Ti 4200. It uses an 8x AGP slot which my motherboard supports and has 128mb of memory.
I have gigabyte onboard LAN and I also installed a second network card. My motherboard can support RAID drives, but I am currently not using this technology. I have one MAXTOR 80GB 7200 IDE hard drive, a very old DVD drive, and a 40x 12x 40x CD-RW. The audio is on-board 5.1 channels and I have a set of Creative 5.1 speakers with a subwoofer.
I used the aluminum tower I had purchased for my previous computer and bought a cheap one for the old system. It has four 5.25" drive bays and two 3.5" ones. There are an additional 3 hidden 3.5" bays inside the case. I installed four additional case fans. The power supply is 450watts.
I have a wireless keyboard and a wired optical mouse simply because I go though too many batteries. My monitor is a ViewSonic VA720 17inch LCD.
In the future I would like to change out my DVD drive for a DVD+-RW and upgrade my video card to one with TV-in capability. I have a SATA drive that failed that I also intend to attempt to fix and use for a dual Linux boot..
Since my computer runs 24/7 for days on end maintenance is very important to me. I run Sygate Firewall and AVG Anti-Virus at all times. I also scan regularly with Ad-Adware SE and Spybot Search and Destroy for spyware. Most of the programs I run are freeware and you can downloading them here if interested. I defrag overnight at least monthly, sometimes more often if I have made many changes to my system. I run SpeedFan at all times to monitor my system temperatures and fans. I also have set BIOS to shut down my computer automatically if it gets too hot.
I use Firefox as my browser and Thunderbird for email because I feel they are more secure than their Microsoft counterparts. I have a couple of flash drives and a 160GB external drive that I use to back up files that change often and everything else I burn to CD's.
