Its been about a year or two since building a new rig, is Arctic Silver 5 still the best?

to the best of my knowledge

Artic Silver is still the one and only...

What's the specs on your new rig?

AMD Phenom II X6 1090T Black Edition
ASUS M4A89TD PRO/USB3 AM3 AMD 890FX
G.SKILL Ripjaws Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 X2 for 8GB

for now then I will be getting a new power supply, 128gb SSD, and another 5850 to crossfire.  Everything else I already have.