Arctic silver is very cool. my system runs on 39C normal and 54 (max i've seen). but make sure you follow instructions carefully.
just keep this in mind, a if u were given choice that the surfaces are so smooth that u may not use thermal interface, then prefer it.
Intel Core2Quad 2.66Ghz 12MB L2-Cache
4096MB DDR Kingston Hyper-X
XFX 9600GT AlphaDog
Seagate 2 X 320GB SATA2
LG L246WH Flatron 24"