Guides/Reviews(see also Computing->Performance):
CNet   PC World   ZDNet   PriceWatch

Cases
(ATX Form Factor / 500 watt PS)
Addtronics   Antec   ChiefMax   Enlight   In-Win  

CD-Writable/Rewritable
(PATA 54x32x54 / USB 52x32x52 / FireWire 52x24x52)
Creative Labs   Hewlett Packard   Hi-Val   Mitsumi   Plextor  

DVD Recorders
(32x R+/R- / Double Layer / Combo with CD-RW / SATA / PATA)
Creative Labs   Hitachi   Hi-Val

Fans/Cooling
3dCool   Cardcooler   CoolerGuys  

Hard Drives
(Serial ATA 1TB / Parallel ATA 750GB / 7200rpm / USB 1TB / Firewire 1TB)
   IBM   Maxtor   Samsung   Seagate   Toshiba   Western Digital

Memory(RAM)
(240pin DDR2 PC2-8500 / 184pin DDR PC6400 / dual-channel / 1GB-2GB)
Crucial   Hitachi   Kingston   Micron   PNY   Rambus   Simple   Viking

Motherboards
(ATX Form Factor; Athlon:Socket AM2/AM2+ - Serial ATA - x16 PCIe - DDR2 - 3xPCI - PCIe(x1))
Chipsets:VIA   AMD   Intel   ALi   SiS
BIOS:BIOS Central   AMI   Award   Phoenix
Motherboards.com   Amptron   Asus   Biostar   Epox   FIC   Gigabyte   Intel   Iwill   Microstar   Shuttle   Soyo   SuperMicro   Tyan

Processors
(AMD: Socket AM2/AM2+ / 6400+ / 64x3 64x4 Phenom / 64x2 Athlon64)
Sandpile.org   AMD   Intel  

Sound/Audio
(PCIe, PCI, Wavetable, Positional)
Creative Labs   Turtle Beach  

Video Cards/Chips
(PCIe x16 / 256-512MB / DirectX 10.1 / nVidia GeForce 8800/8600 / ATI Radeon HD3800/HD2900)
ATI   nVidia   3Dlabs   Appian   Asus   Matrox  


Floppy Drives
Imation   Mitsumi  

Game Controllers
CH Products   Gravis   Logitech   Microsoft   Saitek   Thrustmaster

Home Automation
Advanced Services   BASS   Custom Solutions   Fernbrook   Home Automation Systems   iAutomate   IBM   Smart Home  

Input
Focus   IBM   KeyTronic   Logitech   Microsoft   IBM   Kensington   KeyTronic   Logitech   Microsoft

Modems
(DSL / Cable / Satellite / 56k v92)
3Com/USRobotics   Best Data   Digicom   DirecPC   Motorola   Zoom

Networking
(Wireless 802.11g - 54Mb / 802.11n(draft) - 160Mb)
3Com   AMD   Cisco   D-Link   IBM   Intel   Linksys   SMC   SOHO   Silicon Graphics   Sun

Power Backups/Supplies
APC   Astec   Minuteman   Toshiba