The asus p5q deluxe is about the best going now, although I would have liked a gigabyte UD3 non-L version (4-phase); I can't fault it yet.
This is what I've got so far (copied from a post elsewhere).
I am just proverbially dipping my toe in the water. I think I have a good chance of 3.8Ghz, 450fsb; but wouldn't hesitate to run it higher but I may need some proper pc8500 4Gb ram. I've got either 2x (or 4x) 1Gb crucial pc2-6400c4 (had some just like it at 1150Mhz ages ago), or 2x2Gb corsair xms6400c5 ver3.1 1.8v (possibly good for 472ddr +0.2-0.3v).
Also my +12v is 12.15v according to a DMM not as in speedfan.
Vcore goes from 1.224v load to 1.264v idle ( believe I'm lower than what the bios gave by default, I've been seeing 1.3v in everest for default.)
ASUS P5Q DLX Template :
JumperFree Configuration Settings
AI Overclock tuner: Enabled
CPU Ratio Setting: 8.5
FSB Strap to North Bridge: 333
FSB Frequency: 400
PCI-E Frequency: 100
DRAM Frequency: 5:6
DRAM CLK Skew on Channel A1: AUTO
DRAM CLK Skew on Channel A2: AUTO
DRAM CLK Skew on Channel B1: AUTO
DRAM CLK Skew on Channel B2: AUTO
DRAM Timing Control: Manual
1st Information :
CAS# Latency: 5
DRAM RAS# to CAS# Delay: 5
DRAM RAS# Precharge: 5
DRAM RAS# Activate to Precharge: 18
RAS# to RAS# Delay : AUTO
Row Refresh Cycle Time: 55
Write Recovery Time: AUTO
Read to Precharge Time: AUTO
2nd Information :
READ to WRITE Delay (S/D): AUTO
Write to Read Delay (S): AUTO
WRITE to READ Delay (D): AUTO
READ to READ Delay (S): AUTO
READ to READ Delay (D): AUTO
WRITE to WRITE Delay (S): AUTO
WRITE to WRITE Delay (D): AUTO
3rd Information :
WRITE to PRE Delay: AUTO
READ to PRE Delay: AUTO
PRE to PRE Delay: AUTO
ALL PRE to ACT Delay: AUTO
ALL PRE to REF Delay: AUTO
DRAM Static Read Control: Disabled
DRAM Read Training: AUTO
MEM. OC Charger: AUTO
AI Clock Twister: AUTO
AI Transaction Booster: AUTO
Common Performance Level [5]
Pull-In of CHA PH1: DISABLED
Pull-In of CHA PH2: DISABLED
Pull-In of CHA PH3: DISABLED
Pull-In of CHA PH4: DISABLED
Pull-In of CHB PH1: DISABLED
Pull-In of CHB PH2: DISABLED
Pull-In of CHB PH3: DISABLED
Pull-In of CHB PH4: DISABLED
CPU Voltage: 1.2875
CPU GTL Voltage Reference (0/2): AUTO
CPU GTL Voltage Reference (1/3): AUTO
CPU PLL Voltage: 1.52 (+0.02 over default)
FSB Termination Voltage: 1.22 (+0.02 over default)
DRAM Voltage: 1.9v (Using the old crucial ram like crucial anniversary so I'm not held back by Corsair xms6400c5 2x2Gb)
NB Voltage: 1.22 (+0.02 over default IIRC)
NB GTL Reference: AUTO
SBridge Voltage: 1.1 or minimum
PCIE SATA Voltage: 1.1 or minimum
Load Line Calibration: Disabled
CPU Spread Spectrum: Disabled
PCIE Spread Spectrum: Disabled
CPU Clock Skew : Normal
NB Clock Skew : Normal
Advance CPU Settings
CPU Ratio Setting: Manual
CPU VID: Default
C1E Suppport: Disabled
Max CPUID Value Limit: Disabled
Intel® Virtualization Tech: Disabled
Vanderpool Technology: Disabled
CPU TM Function: Disabled
Execute Disable Bit: Disabled