I'll start with my favorite; ArsTechnica.com:
- Ars System Guide: January 2008 Edition
- Ars System Guide Special: It's Easy Being Green
- Ars System Guide: Spring Forward and Build a New Badass Rig
- Ars System Guide: HTPC Edition
- Ars System Guide: May 2008 Edition
- Ars System Guide: Summer Gaming Edition
- Ars System Guide: September 2008 Edition
- System Guide: the Ars Ultimate Budget Box
- Ars Ultimate Home Theater PC Guide: 1080p HDMI Edition
- TR's Christmas 2007 System Guide
- How To Build a PC
- TR's February 2008 System Guide
- TR's April 2008 System Guide
- TR's Summer 2008 System Guide
- TR's Back to School System Guide
- TR's Fall 2008 System Guide
- TR's Christmas 2008 System Guide
- TR's February 2009 System Guide
- Holiday Buyer's Guide 2007: Part 1
- The Best Gaming Graphics Cards for the Money: November 2007
- Holiday Buyer's Guide 2007: Part 2
- Holiday Buyer's Guide 2007: Part 3 - Games
- Holiday Buyer's Guide 2007: Part 4
- The Best Gaming Graphics Cards for the Money: January 2008
- The Best Gaming Graphics Cards for the Money: February 2008
- The Best Gaming Graphics Cards for the Money: March 2008
- System Builder Marathon: Low Cost System
- System Builder Marathon: Mid Cost System
- System Builder Marathon: High Cost System
- System Builder Marathon: Overclocking
- System Builder Marathon: Price/Performance
- The Best Gaming Graphics Cards for the Money: April 2008
- Tom's Ultimate RAM Speed Tests
- $500 Gaming PC: Day 1, Component Selection
- $500 Gaming PC: Day 2, Testing & Analysis
- The Best Graphics Cards for the Money: May 2008
- Best Graphics Cards for the Money: June 2008
- System Builder Marathon: Sub-$4000 PC
- System Builder Marathon: Sub-$2000 PC
- System Builder Marathon: Sub-$1000 PC
- System Builder Marathon: Overclocking
- Best Graphics Cards for the Money: July '08
- System Builder Marathon: Price/Performance
- Best Graphics Cards for the Money: August '08
- Best Video Cards for the Money: September '08
- Best Video Cards for the Money: Oct '08
- System Builder Marathon: The $4,500 Super PC
- Tom's SBM: The $1,500 Mainstream PC
- System Builder Marathon: $500 Gaming PC
- System Builder Marathon: Performance & Value
- System Builder Marathon: $625 Gaming PC
- System Builder Marathon: $1,250 Enthusiast PC
- System Builder Marathon: Performance & Value
- System Builder Marathon: $625 Gaming PC
- System Builder Marathon: $1,250 Mid-Range PC
- System Builder Marathon: $2,500 Enthusiast PC
- System Builder Marathon: Performance & Value
- Tom's Intl. $750 Cheap Computing Challenge
- System Builder Marathon: $625 Gaming PC
- System Builder Marathon: $1,250 Enthusiast PC
- System Builder Marathon: The $5,000 Extreme PC
- System Builder Marathon: Performance & Value
- How-To: Build an HTPC (With Windows 7)
- The $750 Computing Challenge: Germany vs. USA
- What Does a $16,000+ PC Look Like, Anyway
- Search of Tom's Hardware for "System Builder"
I'd promise to keep this up to date, but we all know that is not likely to happen. In any case, enjoy, and have fun building!